Flexible bandwidth operation in wireless systems

ABSTRACT

Systems, methods, and instrumentalities are disclosed for downlink resource allocation associated with a shared frequency band. A WTRU may receive resource allocation information associated with a component carrier and at least one carrier segment. The component carrier and the least one carrier segment may each comprise a plurality of resource block groups (RBG). At least two bitmaps may be associated with the resource allocation information. A size of a resource block group (RBG) of the component carrier and the at least one carrier segment may be based on a combined number of resource blocks (RB) of the component carrier and the one or more carrier segments divided by a 3GPP Rel-8/Rel-10 RBG size of the component carrier. The WTRU may determine at least one RBG allocated to the WTRU using the resource allocation information and may receive and decode the at least one RBG allocated to the WTRU.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/809,784, filed Nov. 10, 2017, which is a continuation of U.S. patentapplication Ser. No. 14/520,121, filed Oct. 21, 2014, which is acontinuation of U.S. patent application Ser. No. 13/571,656, filed Aug.10, 2012, which issued as U.S. Pat. No. 8,897,253 on Nov. 25, 2014,which claims the benefit of U.S. Provisional Patent Application No.61/522,883, filed Aug. 12, 2011, U.S. Provisional Patent Application No.61/555,887, filed Nov. 4, 2011, and U.S. Provisional Patent ApplicationNo. 61/611,244, filed Mar. 15, 2012, the contents of which are herebyincorporated by reference herein.

BACKGROUND

The Third Generation Partnership Project (3GPP) Long Term Evolution(LTE) standards provide specifications for high performance airinterfaces for cellular mobile communication systems. LTE specificationsare based on Global System for Mobile Communications (GSM)specifications and provide the upgrade path for 3G networks to evolveinto partially-compliant 4G networks. LTE Advanced is an enhancement ofthe LTE standard that provides a fully-compliant 4G upgrade path for LTEand 3G networks.

A goal of 3GPPP and LTE is the simplification of the architecture ofcellular mobile communication systems. One step in simplifying thisarchitecture is transitioning from existing 3GPP universal mobiletelecommunications system (UMTS) combined circuit and packet switchednetworks to pure internet protocol (IP) packet switched systems. Becausethe adoption of LTE is an ongoing process and many mobile devices arenot yet compatible with LTE packet switched technologies, operators ofLTE networks will typically run such networks in conjunction withcircuit-switched networks. This allows network operators to serviceusers of circuit-switched compatible devices as well as users of LTEcompatible devices.

SUMMARY

Systems, methods, and instrumentalities are disclosed for downlinkresource allocation associated with a shared frequency band. A WTRU mayreceive resource allocation information associated with a componentcarrier and at least one carrier segment. The component carrier and theleast one carrier segment may each comprise a plurality of resourceblock groups (RBG). A size of a resource block group (RBG) of thecomponent carrier and a RBG of the at least one carrier segment may bedetermined by a function of bandwidth of the component carrier. At leasttwo bitmaps may be associated with the resource allocation information.The WTRU may determine at least one RBG allocated to the WTRU using theresource allocation information. The WTRU may receive and decode the atleast one RBG allocated to the WTRU.

The resource allocation information may comprise two bitmaps. A firstbitmap may be associated with the RBGs of the component carrier and theRBGs of a first carrier segment. A second bitmap may be associated withthe RBGs of a second carrier segment. A number of bits/RBG for the firstbitmap may be equal to a combined number of resource blocks (RB) in thecomponent carrier and first carrier segment divided by the size of theRBG. A number of bits/RBG for the second bitmap may be equal to a numberof resource blocks (RB) in the second carrier segment divided by thesize of the RBG. If a number of RBGs of the second carrier segment isnot an integer multiple of the size of the RBGs, then a number of nullRBs may be inserted into a last RBG of the second carrier segment suchthat the number of null RBs plus the number of RBs of the second carriersegment is divisible by the size of the RBGs. The number of null RBs maybe variable.

The resource allocation information may comprise three bitmaps. A firstbitmap may be associated with the RBGs of a component carrier. A secondbitmap may be associated with the RBGs of a first carrier segment. Athird bitmap may be associated with the RBGs of a second carriersegment. A number of bits/RBG for the first bitmap, the second bitmap,and the third bitmap may be the number of resource blocks (RB) in therespective carrier divided by the size of the RBG. If the number of RBGsof the component carrier, the first carrier segment, and/or the secondcarrier segment is not an integer multiple of the size of the RBGs, thena number of null RBs may be inserted into the last RBG of the respectivecarrier such that the number of null RBs plus the number of RBs of therespective carrier is divisible by the size of the RBGs.

A WTRU may receive resource allocation information associated with acomponent carrier and at least one carrier segment. The componentcarrier and the least one carrier segment comprising a plurality ofresource block groups (RBG). A size of a resource block group (RBG) ofthe component carrier and the at least one carrier segment may be basedon a scaling factor multiplied by a 3GPP Rel-10 RBG size of thecomponent carrier. The 3GPP Rel-10 RBG size may be determined by thesystem bandwidth of the component carrier. The WTRU may determine atleast one RBG allocated to the WTRU using the resource allocationinformation. The WTRU may receive and decode the at least one RBGallocated to the WTRU.

The scaling factor may be determined by the maximum number of resourceblocks (RB) of the component carrier and the one or more carriersegments. If a combined number of RBs of the one or more carriersegments is less than or equal to the number of RBs of the componentcarrier, then the scaling factor may be two. If a combined number of RBsof the one or more carrier segments is greater than the number of RBs ofthe component carrier, then the scaling factor may be x, wherein xequals a combined number of RBs of the component carrier and the one ormore carrier segments divided by a number of RBs of the componentcarrier.

The resource allocation information may be associated with a bitmap. Anumber of bits for the bitmap may be determined by a combined number ofRBs of the component carrier and the one or more carrier segmentsdivided by the size of a RBG. Two or more consecutive RBs may be groupedtogether into a RBG element according to the size of the RBG. A RB maybe grouped together with one or more nonconsecutive RB into a RBGelement according to the size of the RB G.

A WTRU may receive resource allocation information associated with acomponent carrier and at least one carrier segment. The componentcarrier and the least one carrier segment may comprise a plurality ofresource block groups (RBG). A size of a RBG of the component carrierand the at least one carrier segment may be based on a combined numberof resource blocks (RB) of the component carrier and the one or morecarrier segments divided by a 3GPP Rel-10 RBG size of the componentcarrier. The 3GPP Rel-10 RBG size may be determined by the systembandwidth of the component carrier. The WTRU may determine at least oneRBG allocated to the WTRU using the resource allocation information. TheWTRU may receive and decode the at least one RBG allocated to the WTRU.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented.

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A.

FIG. 1C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 1A.

FIG. 1D is a system diagram of another example radio access network andanother example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 1E is a system diagram of another example radio access network andanother example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 2 is a diagram illustrating example resource block assignmentinformation.

FIG. 3 is a diagram illustrating an example frame structure in LTE.

FIG. 4 is a diagram illustrating an example mapping of a PSS sequence tosubcarriers.

FIG. 5 is a diagram illustrating an example subcarrier mapping for twoSSS short sequences.

FIG. 6 illustrates an example carrier segment structure.

FIGS. 7 to 17 are diagrams illustrating example bitmapping.

FIG. 18 is a diagram illustrating an example DCI transmission for CSs inPDSCH.

FIGS. 19 and 20 are diagrams illustrating examples of numberingprocedures for Physical Resource Blocks (PRB)s.

FIGS. 21 and 22 are diagrams illustrating example mapping of PDSCH incarrier segments.

FIG. 23 is a diagram illustrating an example of PDSCH transmission incarrier segment in MBSFN subframes.

DETAILED DESCRIPTION

A detailed description of illustrative embodiments will now be describedwith reference to the various Figures. Although this descriptionprovides a detailed example of possible implementations, it should benoted that the details are intended to be exemplary and in no way limitthe scope of the application.

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, and/or 102 d (whichgenerally or collectively may be referred to as WTRU 102), a radioaccess network (RAN) 103/104/105, a core network 106/107/109, a publicswitched telephone network (PSTN) 108, the Internet 110, and othernetworks 112, though it will be appreciated that the disclosedembodiments contemplate any number of WTRUs, base stations, networks,and/or network elements. Each of the WTRUs 102 a, 102 b, 102 c, 102 dmay be any type of device configured to operate and/or communicate in awireless environment. By way of example, the WTRUs 102 a, 102 b, 102 c,102 d may be configured to transmit and/or receive wireless signals andmay include user equipment (UE), a mobile station, a fixed or mobilesubscriber unit, a pager, a cellular telephone, a personal digitalassistant (PDA), a smartphone, a laptop, a netbook, a personal computer,a wireless sensor, consumer electronics, and the like.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106/107/109, theInternet 110, and/or the networks 112. By way of example, the basestations 114 a, 114 b may be a base transceiver station (BTS), a Node-B,an eNode B, a Home Node B, a Home eNode B, a site controller, an accesspoint (AP), a wireless router, and the like. While the base stations 114a, 114 b are each depicted as a single element, it will be appreciatedthat the base stations 114 a, 114 b may include any number ofinterconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 103/104/105, which mayalso include other base stations and/or network elements (not shown),such as a base station controller (BSC), a radio network controller(RNC), relay nodes, etc. The base station 114 a and/or the base station114 b may be configured to transmit and/or receive wireless signalswithin a particular geographic region, which may be referred to as acell (not shown). The cell may further be divided into cell sectors. Forexample, the cell associated with the base station 114 a may be dividedinto three sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 115/116/117,which may be any suitable wireless communication link (e.g., radiofrequency (RF), microwave, infrared (IR), ultraviolet (UV), visiblelight, etc.). The air interface 115/116/117 may be established using anysuitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 103/104/105 and the WTRUs 102a, 102 b, 102 c may implement a radio technology such as UniversalMobile Telecommunications System (UNITS) Terrestrial Radio Access(UTRA), which may establish the air interface 115/116/117 using widebandCDMA (WCDMA). WCDMA may include communication protocols such asHigh-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA mayinclude High-Speed Downlink Packet Access (HSDPA) and/or High-SpeedUplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface115/116/117 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106/107/109.

The RAN 103/104/105 may be in communication with the core network106/107/109, which may be any type of network configured to providevoice, data, applications, and/or voice over internet protocol (VoIP)services to one or more of the WTRUs 102 a, 102 b, 102 c, 102 d. Forexample, the core network 106/107/109 may provide call control, billingservices, mobile location-based services, pre-paid calling, Internetconnectivity, video distribution, etc., and/or perform high-levelsecurity functions, such as user authentication. Although not shown inFIG. 1A, it will be appreciated that the RAN 103/104/105 and/or the corenetwork 106/107/109 may be in direct or indirect communication withother RANs that employ the same RAT as the RAN 103/104/105 or adifferent RAT. For example, in addition to being connected to the RAN103/104/105, which may be utilizing an E-UTRA radio technology, the corenetwork 106/107/109 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, 102 d to access the PSTN 108, the Internet 110,and/or other networks 112. The PSTN 108 may include circuit-switchedtelephone networks that provide plain old telephone service (POTS). TheInternet 110 may include a global system of interconnected computernetworks and devices that use common communication protocols, such asthe transmission control protocol (TCP), user datagram protocol (UDP)and the internet protocol (IP) in the TCP/IP internet protocol suite.The networks 112 may include wired or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another core network connected to one or moreRANs, which may employ the same RAT as the RAN 103/104/105 or adifferent RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 130, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment. Also, embodiments contemplate that thebase stations 114 a and 114 b, and/or the nodes that base stations 114 aand 114 b may represent, such as but not limited to transceiver station(BTS), a Node-B, a site controller, an access point (AP), a home node-B,an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a homeevolved node-B gateway, and proxy nodes, among others, may include someor all of the elements depicted in FIG. 1B and described herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in one embodiment,the transmit/receive element 122 may be an antenna configured totransmit and/or receive RF signals. In another embodiment, thetransmit/receive element 122 may be an emitter/detector configured totransmit and/or receive IR, UV, or visible light signals, for example.In yet another embodiment, the transmit/receive element 122 may beconfigured to transmit and receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 115/116/117.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the location of the WTRU 102. In addition to, or inlieu of, the information from the GPS chipset 136, the WTRU 102 mayreceive location information over the air interface 115/116/117 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 103 and the core network 106according to an embodiment. As noted above, the RAN 103 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102 cover the air interface 115. The RAN 103 may also be in communicationwith the core network 106. As shown in FIG. 1C, the RAN 103 may includeNode-Bs 140 a, 140 b, 140 c, which may each include one or moretransceivers for communicating with the WTRUs 102 a, 102 b, 102 c overthe air interface 115. The Node-Bs 140 a, 140 b, 140 c may each beassociated with a particular cell (not shown) within the RAN 103. TheRAN 103 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 103 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 1C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC 142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macrodiversity, security functions, data encryption, and thelike.

The core network 106 shown in FIG. 1C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each ofthe foregoing elements are depicted as part of the core network 106, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 142 a in the RAN 103 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 103 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between and the WTRUs102 a, 102 b, 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1D is a system diagram of the RAN 104 and the core network 107according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the core network 107.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1D, theeNode-Bs 160 a, 160 b, 160 c may communicate with one another over an X2interface.

The core network 107 shown in FIG. 1D may include a mobility managementgateway (MME) 162, a serving gateway 164, and a packet data network(PDN) gateway 166. While each of the foregoing elements are depicted aspart of the core network 107, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 162 may be connected to each of the eNode-Bs 160 a, 160 b, 160 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may also provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 164 may be connected to each of the eNode-Bs 160 a,160 b, 160 c in the RAN 104 via the S1 interface. The serving gateway164 may generally route and forward user data packets to/from the WTRUs102 a, 102 b, 102 c. The serving gateway 164 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 102 a,102 b, 102 c, managing and storing contexts of the WTRUs 102 a, 102 b,102 c, and the like.

The serving gateway 164 may also be connected to the PDN gateway 166,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices.

The core network 107 may facilitate communications with other networks.For example, the core network 107 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 107 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 107 and the PSTN 108. In addition, the corenetwork 107 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1E is a system diagram of the RAN 105 and the core network 109according to an embodiment. The RAN 105 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 102 a, 102 b, 102 c over the air interface 117. As will be furtherdiscussed below, the communication links between the differentfunctional entities of the WTRUs 102 a, 102 b, 102 c, the RAN 105, andthe core network 109 may be defined as reference points.

As shown in FIG. 1E, the RAN 105 may include base stations 180 a, 180 b,180 c, and an ASN gateway 182, though it will be appreciated that theRAN 105 may include any number of base stations and ASN gateways whileremaining consistent with an embodiment. The base stations 180 a, 180 b,180 c may each be associated with a particular cell (not shown) in theRAN 105 and may each include one or more transceivers for communicatingwith the WTRUs 102 a, 102 b, 102 c over the air interface 117. In oneembodiment, the base stations 180 a, 180 b, 180 c may implement MIMOtechnology. Thus, the base station 180 a, for example, may use multipleantennas to transmit wireless signals to, and receive wireless signalsfrom, the WTRU 102 a. The base stations 180 a, 180 b, 180 c may alsoprovide mobility management functions, such as handoff triggering,tunnel establishment, radio resource management, traffic classification,quality of service (QoS) policy enforcement, and the like. The ASNgateway 182 may serve as a traffic aggregation point and may beresponsible for paging, caching of subscriber profiles, routing to thecore network 109, and the like.

The air interface 117 between the WTRUs 102 a, 102 b, 102 c and the RAN105 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 102 a, 102 b, 102 cmay establish a logical interface (not shown) with the core network 109.The logical interface between the WTRUs 102 a, 102 b, 102 c and the corenetwork 109 may be defined as an R2 reference point, which may be usedfor authentication, authorization, IP host configuration management,and/or mobility management.

The communication link between each of the base stations 180 a, 180 b,180 c may be defined as an R8 reference point that includes protocolsfor facilitating WTRU handovers and the transfer of data between basestations. The communication link between the base stations 180 a, 180 b,180 c and the ASN gateway 182 may be defined as an R6 reference point.The R6 reference point may include protocols for facilitating mobilitymanagement based on mobility events associated with each of the WTRUs102 a, 102 b, 102 c.

As shown in FIG. 1E, the RAN 105 may be connected to the core network109. The communication link between the RAN 105 and the core network 109may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 109 may include a mobile IP home agent(MIP-HA) 184, an authentication, authorization, accounting (AAA) server186, and a gateway 188. While each of the foregoing elements aredepicted as part of the core network 109, it will be appreciated thatany one of these elements may be owned and/or operated by an entityother than the core network operator.

The MIP-HA may be responsible for IP address management and may enablethe WTRUs 102 a, 102 b, 102 c to roam between different ASNs and/ordifferent core networks. The MIP-HA 184 may provide the WTRUs 102 a, 102b, 102 c with access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs 102 a, 102 b, 102 cand IP-enabled devices. The AAA server 186 may be responsible for userauthentication and for supporting user services. The gateway 188 mayfacilitate interworking with other networks. For example, the gateway188 may provide the WTRUs 102 a, 102 b, 102 c with access tocircuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. In addition, the gateway 188 mayprovide the WTRUs 102 a, 102 b, 102 c with access to the networks 112,which may include other wired or wireless networks that are owned and/oroperated by other service providers.

Although not shown in FIG. 1E, it will be appreciated that the RAN 105may be connected to other ASNs and the core network 109 may be connectedto other core networks. The communication link between the RAN 105 theother ASNs may be defined as an R4 reference point, which may includeprotocols for coordinating the mobility of the WTRUs 102 a, 102 b, 102 cbetween the RAN 105 and the other ASNs. The communication link betweenthe core network 109 and the other core networks may be defined as an R5reference, which may include protocols for facilitating interworkingbetween home core networks and visited core networks.

3GPP LTE Release 8/9/10/11 operating with a single serving cell(hereafter LTE R8+) may support, for example, up to 100 Mbps in thedownlink (hereafter DL) and 50 Mbps in the uplink (hereafter UL) for a2×2 configuration. The LTE downlink transmission scheme may be based onan OFDMA air interface. For the purpose of flexible deployment, LTE R8+systems may support scalable transmission bandwidths, for example, oneof: 1.4, 2.5, 5, 10, 15 or 20 MHz with 6, 15, 25, 50, 75, 100 resourceblocks, respectively.

In LTE R8+ (and LTE R10+ with carrier aggregation), each radio frame (of10 ms) may consist of 10 equally sized sub-frames of 1 ms. Eachsub-frame may consist of two equally sized timeslots of 0.5 ms each.There may be either 7 or 6 OFDM symbols per timeslot. For example, 7symbols per timeslot may be used with normal cyclic prefix (CP) length,and 6 symbols per timeslot may be used in an alternative systemconfiguration with the extended CP length. The sub-carrier spacing forthe LTE R8/9 system may be 15 kHz. An alternative reduced sub-carrierspacing mode using 7.5 kHz may also be possible.

A resource element (RE) may correspond to one (1) sub-carrier during one(1) OFDM symbol interval. 12 consecutive sub-carriers during a 0.5 mstimeslot may constitute one (1) resource block (RB). For example, with 7symbols per timeslot, each RB may consist of 12*7=84 RE's. A DL carriermay include a scalable number of resource blocks (RBs), ranging from aminimum of 6 RBs up to a maximum of 110 RBs, for example. This maycorrespond to an overall scalable transmission bandwidth of roughly 1MHz up to 20 MHz. A set of common transmission bandwidths may bespecified (e.g., 1.4, 3, 5, 10, 15 and/or 20 MHz).

The basic time-domain unit for dynamic scheduling may be one sub-frameconsisting of two consecutive timeslots. This may be referred to as aresource-block pair. Certain sub-carriers on some OFDM symbols may beallocated to carry pilot signals in the time-frequency grid. Forexample, a given number of sub-carriers at the edges of the transmissionbandwidth may not be transmitted in order to comply with spectral maskuses.

Scheduling principles and downlink control signalling may be describedherein. For example, in a LTE R8+ system, the NW may control physicalradio resources using the Physical Downlink Control Channel (hereafterPDCCH). Control messages may be transmitted using specific formats(e.g., DCI formats). For example, the WTRU may determine whether or notit is to act on control signaling in a given sub-frame by monitoring thePDCCH for specific data control information messages (hereafter DCIformats) scrambled using a known radio network temporary identifier(hereafter RNTI) in specific locations, and/or search space, usingdifferent combinations of physical resources (e.g., control channelelements—hereafter CCEs) based on aggregation levels (hereafter AL, eachcorresponding to either 1, 2, 4, or 8 CCEs). A CCE may consist of 36QPSK symbols or 72 channel coded bits.

Which DCI formats the WTRU decodes may depend on the configuredtransmission mode (e.g., whether or not spatial multiplexing is used).There may be a number of different DCI formats (e.g., format 0 (ULgrant), formats 1 (non-MIMO), formats 2 (DL MIMO) and/or formats 3(power control)). The format of the control messages may be defined in3GPP TS 36.212: “Evolved Universal Terrestrial Radio Access (E-UTRA);Multiplexing and Channel Coding,” the contents of which are hereinincorporated by reference.

The version of one or more of the DCI format(s) the WTRU decodes may begoverned at least in part by the configured transmission mode (e.g.,modes 1-7 for R8 and R9).

A list with usage may be presented below:

-   -   (1) DCI format 0 (UL grant)    -   (2) DCI format 1 (DL assignment)    -   (3) DCI format 1A (compact DL assignment/PDCCH order for random        access)    -   (4) DCI format 1B (DL assignment with precoding info)    -   (5) DCI format 1C (very compact DL assignment)    -   (6) DCI format 1D (compact DL assignment with precoding        info+power offset information)    -   (7) DCI format 2 (DL assignment for spatial multiplexing)    -   (8) DCI format 2A    -   (9) DCI format 3 (TPC for PUCCH/PDSCH, two bits)    -   (10) DCI format 3A (TPC for PUCCH/PDSCH, single bit)

Table 1 illustrates examples of different DCI sizes resulting fromdifferent system bandwidth configurations.

TABLE 1 Bandwidth 6 15 25 50 75 100 Format 0 37 38 41 43 43 44 Format 1A37 38 41 43 43 44 Format 3/3A 37 38 41 43 43 44 Format 1C 24 26 28 29 3031 Format 1 35 39 43 47 49 55 Format 1B (2 tx ant) 38 41 43 44 45 46Format 1D (2 tx ant) 38 41 43 44 45 46 Format 2 (2 tx ant) 47 50 55 5961 67 Format 2A (2 tx ant) 44 47 52 57 58 64 Format 1B (4 tx ant) 41 4344 46 47 49 Format 1D (4 tx ant) 41 43 44 46 47 49 Format 2 (4 tx ant)50 53 58 62 64 70 Format 2A (4 tx ant) 46 49 54 58 61 66

For example, in LTE R8+ systems, whether the control signaling receivedon PDCCH pertains to the uplink component carrier or to the downlinkcomponent carrier may be related to the format of the DCI decoded by theWTRU. The DCI formats may be used to control the WTRUs communication onthe uplink component carrier and/or on the downlink component carrier ofthe cell on which the WTRU is connected.

Downlink transmission modes may be described herein. For example, in LTEsystems, a number of multi-antenna transmission modes may be supported.Each mode may be referred to as a transmission mode. Each mode maydiffer in how the input to each antenna port is mapped as well as whatreference signals may be used for demodulation. The followingtransmission modes (hereafter TM) may be defined for DL-SCHtransmissions:

-   -   (1) TM1: Single-antenna transmission.    -   (2) TM2: Transmit diversity.    -   (3) TM3: Open-loop codebook-based precoding, if more than one        layer, else transmit diversity if rank-one transmission.    -   (4) TM4: Closed-loop codebook-based precoding.    -   (5) TM5: Multi-user-MIMO version of TM4.    -   (6) TM6: Codebook-based precoding limited to single layer        transmission.    -   (7) TM7: R8 non-codebook-based precoding with single layer        transmission.    -   (8) TM8: R9 non-codebook-based precoding supporting up to two        layers.    -   (9) TM9: R10 non-codebook-based precoding supporting up to eight        layers.

The WTRU may interpret the resource allocation field depending on thePDCCH DCI format detected. A resource allocation field in each PDCCH mayinclude at least a resource allocation header field and informationconsisting of the actual resource block assignment. PDCCH DCI formats 1,2, 2A, 2B and 2C with type 0 and PDCCH DCI formats 1, 2, 2A, 2B and 2Cwith type 1 resource allocation may have the same format and may bedistinguished from each other via the single bit resource allocationheader field which exists depending on the downlink system bandwidth,where type 0 may be indicated by 0 value and type 1 may be indicatedotherwise. PDCCH with DCI format 1A, 1B, 1C and 1D may have a type 2resource allocation while PDCCH with DCI format 1, 2, 2A, 2B and 2C mayhave type 0 or type 1 resource allocation. PDCCH DCI formats with a type2 resource allocation may not have a resource allocation header field.The summary of the types may be described herein.

For example, as shown below, in resource allocations of type 0, resourceblock assignment information may include a bitmap indicating theresource block groups (RBGs) that are allocated to the scheduled WTRUwhere a RBG0 may be a set of consecutive virtual resource blocks (VRBs)of localized type. Resource block group size (P) may be a function ofthe system bandwidth, for example, as shown in Table 2. Table 2illustrates an example of Type 0 Resource Allocation RBG Size vs.Downlink System Bandwidth.

TABLE 2 System RBG Bandwidth N_(RB) ^(DL) Size (P) ≤10 1 11-26 2 27-63 3 64-110 4

The total number of RBGs (N_(RBG)) for downlink system bandwidth ofN_(RB) ^(DL) may be given by N_(RBG)=┌N_(RB) ^(DL)/P┐, where └N_(RB)^(DL)/P┘ of the RBGs may be of size P, and if N_(RB) ^(DL) mod P>0 thenone of the RBGs may be of size N_(RB) ^(DL)−P·└N_(RB) ^(DL)/P┘. Forexample, the bitmap may be of size N_(RBG) bits with one bitmap bit perRBG such that each RBG may be addressable. The RBGs may be indexed inthe order of increasing frequency and non-increasing RBG sizes startingat the lowest frequency. For example, the order of RBG to bitmap bitmapping may be such that RBG 0 to RBGN_(RBG)−1 may be mapped to mostsignificant bit (MSB) to least significant bit (LSB) of the bitmap. TheRBG may be allocated to the WTRU if the corresponding bit value in thebitmap is 1 and the RBG is not allocated to the WTRU otherwise.

The Type 0 Resource allocation field in a DCI format is illustrated asfollows:

Type 0 Resource Allocation Field Type Bitmap

In resource allocations of type 1, resource block assignment informationof size N_(RBG) may indicate to a scheduled WTRU the VRBs from the setof VRBs from one of P RBG subsets. The virtual resource blocks used maybe of localized type. P may be the RBG size associated with the systembandwidth, for example, as shown in Table 2. A RBG subset p, where0≤p<P, may consist of the P th RBG (e.g., every P th RBG) starting fromRBG p. The resource block assignment information may consist of one ormore fields, for example, as shown in FIG. 2 . Referring to FIG. 2 , thefirst field with ┌log₂ (P)┐ bits may be used to indicate the selectedRBG subset among P RBG subsets. The second field with one bit may beused to indicate a shift of the resource allocation span within asubset. For example, a bit value of 1 may indicate shift is triggeredand/or shift is not triggered. The third field may include a bitmap, forexample, where each bit of the bitmap may address a single VRB in theselected RBG subset such that the MSB to the LSB of the bitmap may bemapped to the VRBs in the increasing frequency order. For example, theVRB may be allocated to the WTRU if the corresponding bit value in thebit field is 1, otherwise the VRB may not be allocated to the WTRU. Theportion of the bitmap used to address VRBs in a selected RBG subset mayhave size N_(RB) ^(TYPE1) and may be defined asN _(RB) ^(TYPE1) =┌N _(RB) ^(DL) /P┐−┌log₂(P)┐−1.

For example, the addressable VRB numbers of a selected RBG subset maystart from an offset, Δ_(shift) (P) to the smallest VRB number withinthe selected RBG subset, which may be mapped to the MSB of the bitmap.The offset may be in terms of the number of VRBs and may be done withinthe selected RBG subset. If the value of the bit in the second field forshift of the resource allocation span is set to 0, the offset for RBGsubset p may be given by Δ_(shift)(P)=0. Otherwise, the offset for RBGsubset p may be given by, for example, Δ_(shift)(p)=N_(RB)^(RBG subset)(p)−N_(RB) ^(TYPE1) where the LSB of the bitmap may bejustified with the highest VRB number within the selected RBG subset.N_(RB) ^(RBG subset)(p) may be the number of VRBs in RBG subset p andmay be calculated by:

${N_{RB}^{{RBG}\mspace{14mu}{subset}}(p)} = \left\{ \begin{matrix}{{{\left\lfloor \frac{N_{RB}^{DL} - 1}{P^{2}} \right\rfloor \cdot P} + P},} & {p < {\left\lfloor \frac{N_{RB}^{DL} - 1}{P} \right\rfloor{mod}\; P}} \\{{{\left\lfloor \frac{N_{RB}^{DL} - 1}{P^{2}} \right\rfloor \cdot P} + {\left( {N_{RB}^{DL} - 1} \right){mod}\mspace{14mu} P} + 1},} & {p = {\left\lfloor \frac{N_{RB}^{DL} - 1}{P} \right\rfloor{mod}\; P}} \\{{\left\lfloor \frac{N_{RB}^{DL} - 1}{P^{2}} \right\rfloor \cdot P},} & {p > {\left\lfloor \frac{N_{RB}^{DL} - 1}{P} \right\rfloor{{mod}P}}}\end{matrix} \right.$

For example, when RBG subset p may be indicated, bit i for i=0, 1, . . ., N_(RB) ^(TYPE1)−1 in the bitmap field may indicate the VRB number,

${n_{VRB}^{{RBG}\;{subset}}(p)} = {{\left\lfloor \frac{i + {\Delta_{shift}(p)}}{P} \right\rfloor P^{2}} + {p \cdot P} + {\left( {i + {\Delta_{shift}(p)}} \right){mod}\;{P.}}}$

Type 1 Resource allocation field in a DCI format in illustrated below:

Type 1 Resource allocation field Type Subset Shift Bitmap

The following example (N_(RB) ^(DL)=50) may illustrate how to constructtype 1 RA based on the above R10 alogrithms. From Table 2, for N_(RB)^(DL)=50, the RBG subsets P may be 3, which uses ┌log₂ P┐=2 bits and thesize of bitmap may be calculated by subtracting the number of bits forthe subset field and 1 bit for the shift field as N_(RBG)=┌N_(RB)^(DL)/P┐−┌log₂ P┐−1=14 bits. FIG. 2 may show RB numbers per subset withthe shift bit (reset/set). The first 3 (P=3) consecutive RBs (0 to 2)may be assigned to the subset 0, the next 3 consecutive RBs (3 to 5) tothe subset 1, the next 3 consecutive RBs (6 to 8) to the subset 2. Theprocedure may be repeated until the bitmaps (e.g., all bitmaps) arefilled. In order to obtain a shift value for each subset, extra columns(the last 4 columns of 14 to 17) may be extended until the last valid RB(49 for N_(RB) ^(DL)=50) may be filled with its group of nine (=P²) RBs(45 to 53). A shift value may be extracted by shifting valid RBs intothe bitmap. For example, 4 shifts of valid RBs (38 to 47) for subset 0,3 shifts of (41 to 49) for subset 1, and 1 shift of (44) for subset 2.

For example, in resource allocations of type 2, the resource blockassignment information may indicate to a scheduled WTRU a set ofcontiguously allocated localized virtual resource blocks and/ordistributed virtual resource blocks. In case of resource allocationsignaled with PDCCH DCI format 1A, 1B and/or 1D, one bit flag mayindicate whether localized virtual resource blocks and/or distributedvirtual resource blocks may be assigned (e.g., value 0 may indicateLocalized and value 1 may indicate Distributed VRB assignment) whiledistributed virtual resource blocks may be assigned (e.g., alwaysassigned) in case of resource allocation signaled with PDCCH DCI format1C. Localized VRB allocations for a WTRU may vary from a single VRB upto a maximum number of VRBs spanning the system bandwidth. For DCIformat 1A, the distributed VRB allocations for a WTRU may vary from asingle VRB up to N_(VRB) ^(DL) VRBs, where N_(VRB) ^(DL) may be definedin 3 GPP TS 36.212, if the DCI CRC is scrambled by P-RNTI, RA-RNTI,and/or SI-RNTI. With PDCCH DCI format 1B, 1D, and/or 1A with a CRCscrambled with C-RNTI, distributed VRB allocations for a WTRU may varyfrom a single VRB up to N_(VRB) ^(DL) VRBs, if N_(VRB) ^(DL) may be 6-49and may vary from a single VRB up to 16, if N_(RB) ^(DL) may be 50-110.With PDCCH DCI format 1C, distributed VRB allocations for a WTRU mayvary from N_(RB) ^(step) VRB(s) up to ┌N_(VRB) ^(DL)/N_(RB)^(step)┘·N_(RB) ^(step) VRBs with an increment step of N_(RB) ^(step),where N_(RB) ^(step) value may be determined depending on the downlinksystem bandwidth, for example, as shown in Table 3 illustrating N_(RB)^(step) values vs. Downlink System Bandwidth.

TABLE 3 System N_(RB) ^(step) BW (N_(RB) ^(DL)) DCI format 1C 6-49 250-110 4

For PDCCH DCI format 1A, 1B and/or 1D, a type 2 resource allocationfield may consist of a resource indication value (RIV) corresponding toa starting resource block (RB_(start)) and a length in terms ofvirtually contiguously allocated resource blocks L_(CRBs). The resourceindication value may be defined by:if (L _(CRBs)−1)≤┌N _(RB) ^(DL)/2┘ thenRIV=N _(RB) ^(DL)(L _(CRBs)−1)+RB_(start)elseRIV=N _(RB) ^(DL)(N _(RB) ^(DL) −L _(CRBs)+1)+(N _(RB)^(DL)−1−RB_(start))

-   -   where L_(CRBs)≥1 and may not exceed N_(VRB) ^(DL)−RB_(start).

For PDCCH DCI format 1C, a type 2 resource block assignment field mayconsist of a resource indication value (RIV) corresponding to a startingresource block (RB_(start)=0, N_(RB) ^(step), 2N_(RB) ^(step), . . . ,(┌N_(VRB) ^(DL)/N_(RB) ^(step)┐−1)N_(RB) ^(step)) and a length in termsof virtually contiguously allocated resource blocks (L_(CRBs)=N_(RB)^(step), 2N_(RB) ^(step), . . . , ┌N_(VRB) ^(DL)/N_(RB) ^(step)┐·N_(RB)^(step)). The resource indication value may be defined by:if (L′ _(CRBs)−1)≤┌N′ _(VRB) ^(DL)/2┐ thenRIV=N′ _(VRB) ^(DL)(L′ _(CRBs)−1)+RB′_(start)elseRIV=N′ _(VRB) ^(DL)(N′ _(VRB) ^(DL) −L′ _(CRBs)+1)+(N′ _(VRB)^(DL)−1−RB′_(start))

-   -   where L′_(CRBs)=L_(CRBs)/N_(RB) ^(step),        RB′_(start)=RB_(start)/N_(RB) ^(step) and N′_(VRB)        ^(DL)=┌N_(VRB) ^(CL)/N_(RB) ^(step)┐.    -   Here, L′_(CRBs)≥1 and may not exceed N′_(VRB) ^(DL)−RB′_(start).

Resource Allocation for PDCCH with uplink DCI Format. Two resourceallocation schemes Type 0 and Type 1 may be supported for PDCCH withuplink DCI format where the selected resource allocation type for adecoded PDCCH may be indicated by a resource allocation type bit wheretype 0 may be indicated by 0 value and/or type 1 may be indicatedotherwise. The WTRU may interpret the resource allocation fielddepending on, for example, the resource allocation type bit in theuplink PDCCH DCI format detected.

The resource allocation information for uplink resource allocation type0 may indicate to a scheduled WTRU a set of contiguously allocatedvirtual resource block indices denoted by n_(VRB). A resource allocationfield in the scheduling grant may consist of a resource indication value(RIV) corresponding to a starting resource block (RB_(START)) and alength in terms of contiguously allocated resource blocks (L_(CRBs)≥1).The resource indication value may be defined by:if (L _(CRBs)−1)≤┌N _(RB) ^(UL)/2┘ thenRIV=N _(RB) ^(UL)(L _(CRBs)−1)+RB_(START)elseRIV=N _(RB) ^(UL)(N _(RB) ^(UL)(N _(RB) ^(UL) −L _(CRBs)+1)+(N _(RB)^(UL)−1−RB_(START))

The resource allocation information for uplink resource allocation type1 may indicate to a scheduled WTRU two sets of resource blocks. Forexample, a set may include one or more consecutive resource block groupsof size P, for example, as given in Table 2 for uplink system bandwidthN_(RB) ^(UL). A resource allocation field in the scheduling grant mayconsist of a combinatorial index r corresponding to a starting andending RBG index of resource block set 1, s₀ and s₁−1, and resourceblock set 2, s₂ and s₃−1 respectively, where r may be given by:

$r = {\sum\limits_{i = 0}^{M - 1}\left\langle \begin{matrix}{N - s_{i}} \\{M - i}\end{matrix} \right\rangle}$with M=4 and N=└N_(RB) ^(UL)/P┘+1 Below, ordering properties and rangeof values that S_(i) (RBG indices) map to may be defined. A single RBGmay be allocated for a set at the starting RBG index if thecorresponding ending RBG index equals the starting RBG index.

For example, in LTE R8+ systems, the WTRU may receive a cell-specificdownlink reference signal for different purposes. Cell-specificReference Signals (hereafter CRS). A WTRU may use the CRS for channelestimation for coherent demodulation of any downlink physical channel.There may be an exception for PMCH and/or for PDSCH when configured withTM7, TM8 or TM9. The WTRU may use the CRS for channel state information(CSI) measurements. The WTRU may use the CRS for cell-selection and/ormobility-related measurements. CRS may be received in any subframes.There may be one CRS for each antenna ports (e.g., 1, 2, and/or 4). ACRS may occupy the first, third, and/or last OFDM symbol of each slot.

The WTRU may receive one or more of the following downlink referencesignals. Demodulation Reference Signals (hereafter DM-RS). AWTRU-specific reference signal may be used for channel estimation fordemodulation of PDSCH with TM7, TM8 and TM9. The DM-RS may betransmitted in the resource blocks assigned to the PDSCH transmissionfor the concerned WTRU.

CSI Reference Signals (hereafter CSI-RS). A WTRU may use the CSI-RS forchannel state information measurements. CSI-RS may be used (e.g., onlyused) for TM9, and may be less densely transmitted by the network thanthe CRS.

Synchronization Signal and Physical Broadcast Channel (hereafter PBCH).The WTRU may obtain synchronization, may detect the identity of the cell(hereafter cell ID), and/or may determine the length (normal/extended)of the cyclic prefix using synchronization signals (e.g., which may bebased on the difference in duration between the primary and thesecondary synchronization signals).

For example, the primary and secondary synchronization signals (i.e.,PSS, SSS) may be transmitted on the 62 subcarriers out of 72 subcarriers(5 subcarriers on each side of edge may be reserved and not used)centered on the DC subcarrier in the last OFDM symbol and the 2nd lastOFDM symbol of slot 0 and slot 10 of each frame respectively in FDD. Anexample of such may be shown in FIG. 3 . Referring to FIG. 3 , the PSSmay be located in the 3rd OFDM symbol in subframes 1 and 6 and SSS inthe last OFDM symbol in slot 1 and 11 in TDD.

A purpose of the synchronization signals may be to enable acquisition ofthe symbol timing and initial frequency of the downlink carrier signal.The synchronizations signals may convey information regarding the CellID.

There may be three PSS sequences defined in LTE. The one transmitted maybe a function of the cell ID and may aid in the cell search process. Thethree PSSs may be constructed based on Zadoff-Chu (ZC) sequence p_(u)(n)of length 62 (truncated from 63) extended with five zeros at the edges.The d_(u)(n) sequence may be defined as:

${d_{u}(n)} = \left\{ \begin{matrix}e^{{- j}\;\frac{\pi\;{{un}{({n + 1})}}}{63}} & {{n = 0},1,\ldots\mspace{11mu},30} \\e^{{- j}\frac{\pi\;{u{({n + 1})}}{({n + 2})}}{63}} & {{n = 31},32,\ldots\mspace{11mu},61}\end{matrix} \right.$

where the ZC root sequence index u may be given by u={25, 29, 34} forNg_(ID) ⁽²⁾={0, 1, 2} which may represent the physical-layer identitywithin the physical-layer cell-identity group.

FIG. 4 illustrates an example of the mapping of the d_(u) ^((n))sequence to the central subcarriers around DC subcarrier in thefrequency-domain.

LTE cell search step 1 may consist of one or more of the followingtasks: Acquiring a coarse estimate of the carrier frequency offset(CFO); Acquiring a coarse estimate of the OFDM symbol timing offset(STO); and/or Detecting the Primary Synchronization Signal (PSS) index(i.e., cell identity within the cell-identity group which belongs to theset of N_(ID) ⁽²⁾={0, 1, 2}).

Cell search step 1 may determine the 5 ms timing of the cell (i.e., halfframe timing) and/or the location of the Secondary SynchronizationSignal (SSS) that may be used by CS step 2. Cell Search Step 2 mayextract one or more of the following information from the received SSSsignals: Cell ID group, N_(ID) ⁽¹⁾=(0˜167); Frame boundary (subframe 0or 5); and/or CP length (short or long).

The 62 subcarriers of SSS may be interlaced with two length-31 binarysequences, s₀ and s₁, for example, as shown in FIG. 5 . Referring toFIG. 5 , s₁ may be denoted by a white block, while s₂ may be denoted bya black block. The interlaced sequence may be scrambled with ascrambling sequence, c₀ and c₁, which may be given by the primarysynchronization signal and then with a scrambling sequence, z₁. Thecombination of two length-31 sequences defining SSS signal may differbetween subframe 0 and subframe 5 according to

${d\left( {2n} \right)} = \left\{ {{\begin{matrix}{{s_{0}^{(m_{0})}(n)}{c_{0}(n)}} & {{in}\mspace{14mu}{subframe}\mspace{14mu} 0} \\{{s_{1}^{(m_{1})}(n)}{c_{0}(n)}} & {{in}\mspace{14mu}{subframe}\mspace{14mu} 5}\end{matrix}{d\left( {{2n} + 1} \right)}} = \left\{ \begin{matrix}{{s_{1}^{(m_{1})}(n)}{c_{1}(n)}{z_{1}^{(m_{0})}(n)}} & {{in}\mspace{14mu}{subframe}\mspace{14mu} 0} \\{{s_{0}^{(m_{0})}(n)}{c_{1}(n)}{z_{1}^{(m_{1})}(n)}} & {{in}\mspace{14mu}{subframe}\mspace{14mu} 5}\end{matrix} \right.} \right.$where 0≤n≤30. The binary sequences (s₀, s₁), (c₀, c₁), and z₁ may bemaximal length sequences generated according to a generation function ofx⁵+x²+1, x⁵+x³+1, and x⁵+x⁴+x²+x+1 respectively. The indices m0 and m1may represent cyclic shifts and may be derived from the physical-layercell-identity group N_(ID) ⁽¹⁾.

Referring to FIG. 3 , the coded BCH transport block may be mapped to thefirst subframe of each frame in four consecutive frames (40 ms timing)and may be transmitted within the first four OFDM symbols of the secondslot of subframe 0 and over the 72 center subcarriers. In case of FDD,BCH may follow after the PSS/SSS in subframe 0. Since BCH scrambling maybe defined with 40 ms periodicity, a WTRU may attempt to decode the BCHat four possible frame timing position such that the WTRU may implicitlydetermine 40 ms timing or equivalently the two least significant bits ofSFN.

The WTRU may receive the Master Information block (hereafter MIB) on thePBCH. The MIB may comprise PHICH information, downlink bandwidth, and/orsystem frame number. The WTRU may use the PBCH to blindly detect thenumber of transmit antenna port(s) for which detection may be verifiedusing the PBCH CRC.

Cell selection and re-selection may be described herein. In order for aWTRU to obtain normal service, it may camp onto a “suitable cell” whichmay fulfill one or more of the following criterion: The cell may be partof the selected PLMN, the registered PLMN, and/or a PLMN of theEquivalent PLMN list. According to the latest information provided byNAS: the cell may not be barred; the cell may be part of at least one TAthat may not be part of the list of “forbidden tracking areas forroaming,” which may belong to a PLMN that may fulfill one or more of thecriterion listed herein; the cell selection criteria may be fulfilled;and/or for a CSG cell, the CSG ID may be part of the CSG whitelist ofthe WTRU.

Cell selection may be the process in which WTRU may attempt to find andcamp on a suitable cell in order to establish normal service with thenetwork. The selection process may be based on a previously stored setof cell information (e.g., stored cell selection) and/or having no priorknowledge of LTE cells or LTE carriers (e.g., initial cell selection).In case of initial cell selection, the WTRU may scan one or more RFchannels in the E-UTRA bands. The WTRU may search for and detect thestrong cell in each carrier frequency to find a suitable cell. Once acandidate for a suitable cell has been found, the WTRU may then camponto that cell and read the system information (e.g., MIB, SIB1, etc.)to obtain information about the cell and/or PLMN. The WTRU may attemptto establish a connection to the network. If the cell is considered notsuitable based on the above criterion and/or if reading attempts of thebroadcast information has failed, the WTRU may move onto the nextcandidate cell and repeat the cell selection process.

Cell reselection may be a process where the WTRU continually monitorsneighboring cells while camped onto a suitable serving cell to see ifbetter quality suitable cells become available. WTRU may measureneighbor cells when the quality of the serving cell begins to diminish.Information of neighbor cells may also be provided through the systembroadcast information (i.e., SIB3, 4, 5) of the serving cell. The WTRUmay autonomously detect neighboring cells as candidate cells forre-selection. The WTRU may continually detect, measure, and/or evaluatepossible neighboring cells until a particular cell meets the cellre-selection criteria. At which point, the WTRU may attempt to camp onthe re-selected cell and attempt to read its system information forsuitability. If the criteria on the re-selected cell has been met as asuitable cell, the WTRU may continue to camp on the re-selected cell andcontinue to be provided with normal service.

As part of the measurement and neighboring cell information received bythe WTRU from the serving cell, there may be a black list. The blacklist may comprise a list of cell PCIs, which may not be deemed suitableand as such may be removed as possible candidates for re-selection.

Bandwidth extensions and/or Carrier Aggregation (hereafter CA) may beused to increase data rates. For example, with CA, the WTRU may transmitand receive simultaneously over the PUSCH and the PDSCH (respectively)of multiple serving cells (e.g., up to five serving cells with orwithout configured uplink resources). The serving cells may be used tosupport flexible bandwidth assignments up to. For example, 100 MHz. Inaddition to the baseline functionality of LTE R8+, a number ofadditional methods may be introduced to support the simultaneousoperation of a WTRU on multiple serving cells.

Cross-carrier scheduling for carrier aggregation may be describedherein. The control information for the scheduling of PDSCH and/or PUSCHmay be sent on one or more PDCCH(s). In addition to, for example, theLTE R8+ scheduling using one PDCCH for a pair of UL and DL carriers,cross-carrier scheduling may also be supported on the PDCCH of a servingcell (e.g., the PCell), which may allow the network to provide PDSCHassignments and/or PUSCH grants for any other serving cell (e.g., aSCell). When cross-carrier scheduling is used, a 3-bit Carrier IndicatorField (hereafter CIF) may be used to address the concerned SCell, whereeach SCells identifier may be derived from RRC configuration.

“Carrier segment” may refer a set of physical resource blocks on whichthe WTRU may operate. A WTRU may be configured with one or more carriersegment(s) for a given serving cell. If carrier aggregation isconfigured, the serving cell may be a PCell or a SCell of the WTRU'sconfiguration. A carrier segment may be a contiguous bandwidth extensionto the addressable range of resource blocks typically supported for theconcerned serving cell.

FIG. 6 illustrates an example carrier segment structure. Referring toFIG. 6 , the carrier bandwidth may be B MHz, where the set of supportedcentral B₀ MHz frequency may be defined for each standard Release. Whenconfigured to operate on the concerned serving cell, the WTRU mayinitially operate using the nominal carrier bandwidth of B₀ MHz and maysubsequently be configured such that the extended bandwidth representedby the additional segments (B_(D) and/or B_(U)), which may be consideredas a group of resource blocks that extend the nominal bandwidth of thecarrier.

A carrier segment can be viewed as an extension (e.g., a new extension)to the WTRU's physical resource map on which transmissions (e.g., uplinkand/or downlink) may be scheduled by the network.

“Extension carrier” may refer to a carrier (e.g., a supplementarycarrier) on which the WTRU may operate. An extension carrier may bereferred to as an additional carrier or carrier type, a new R11 carrier,or a future release carrier.

A WTRU may be configured with one or more serving cells on which it mayoperate according to the extension carrier. The concerned serving cellmay be a SCell of the WTRU's multicarrier configuration, for example,with (SCell DL+SCell UL) or without (SCell DL) configured uplinkresources. This may or may not exclude the case where a SCell may beconfigured (e.g., only configured) for uplink transmissions, forexample, if the SCell UL may be in the same band as the PCell of theWTRU's configuration.

The WTRU may perform at least one of the following for a SCellconfigured as an extension carrier: (1) the WTRU may receive downlinktransmissions (SCell DL) (e.g., on PDSCH); (2) the WTRU may performuplink transmissions (SCell UL) (e.g., on PUSCH); (3) the WTRU mayreceive reference signals (e.g., a cell-specific CRS and/orWTRU-specific DM-RS and/or CSI-RS); and/or (4) a WTRU may transmitSounding and Reference Signals (hereafter SRS) signals.

The WTRU may or may not be used to perform one or more of the followingfor a serving cell configured as an extension carrier: (1) receiveprimary (hereafter PSS) and/or secondary (hereafter SSS) synchronizationsignals; (2) receive broadcasted System Information (SI) (e.g., on theBCCH (if present)); and/or (3) receive and decode downlink controlsignaling on the physical control channels of the concerned serving cell(e.g., the PDCCH and/or the PHICH and/or the PCFICH (if present)).

The SCell configured as an extension carrier may or may not bebackward-compatible with R10 SCell operation. Given the absence of thecell-specific synchronization signals and/or reference signals, thebroadcast of system information and/or downlink control signaling, amongothers, operation in the concerned serving cell may or may not bebackward compatible for a single carrier WTRU (e.g., either a R8 WTRU, aR9 WTRU, and/or a R10 or above WTRU that may not support carrieraggregation) and/or for initial access for any type of WTRU.

“Component Carrier (CC)” may refer to a frequency on which the WTRU mayoperate. For example, a WTRU may receive transmissions on a downlink CC(hereafter “DL CC”). A DL CC may comprise of a plurality of DL physicalchannels. For example, a WTRU may perform transmissions on an uplink CC(hereafter “UL CC”). A UL CC may comprise of a plurality of UL physicalchannels. For example, for LTE the downlink physical channels mayinclude the Physical Control Format Indicator Channel (PCFICH), thePhysical Hybrid ARQ Indicator Channel (PHICH), the Physical Data ControlChannel (PDCCH), the Physical Multicast data Channel (PMCH), and/or thePhysical Data Shared Channel (PDSCH). On the PCFICH, the WTRU mayreceive control data indicating the size of the control region of the DLCC. On the PHICH, the WTRU may receive control data indicating HARQAcknowledgement/Negative Acknowledgement (hereafter HARQ A/N, HARQACK/NACK and/or HARQ-ACK) feedback for a previous uplink transmission.On the PDCCH, the WTRU may receive downlink control information (DCIs)messages that may be used for scheduling of downlink and uplinkresources. On the PDSCH, the WTRU may receive user and/or control data.For example, a WTRU may transmit on an UL CC.

For LTE, the uplink physical channels may include the Physical UplinkControl Channel (PUCCH) and/or the Physical Uplink Shared Channel(PUSCH). On the PUSCH, the WTRU may transmit user data and/or controldata. On the PUCCH, and in certain cases on the PUSCH, the WTRU maytransmit uplink control information (such as, but not limited to,CQI/PMI/RI or SR) and/or hybrid automatic repeat request (HARQ)acknowledgement/negative acknowledgement (ACK/NACK) feedback. On a ULCC, the WTRU may be allocated dedicated resources for transmission ofSounding and Reference Signals (SRS).

A cell may consist in a DL CC which may be linked to a UL CC based on,for example, the system information (SI) received by the WTRU eitherbroadcasted on the DL CC and/or using dedicated configuration signalingfrom the network. For example, when broadcasted on the DL CC, the WTRUmay receive the uplink frequency and bandwidth of the linked UL CC aspart of the system information element (e.g., when in RRC_IDLE for LTE,or when in idle/CELL_FACH for WCDMA, e.g., when the WTRU does not yethave a radio resource connection to the network).

The “Primary Cell (PCell)” may refer to the cell operating of theprimary frequency in which the WTRU may perform the initial access tothe system (e.g., in which it either performs the initial connectionestablishment procedure or initiates the connection re-establishmentprocedure, and/or the cell indicated as the primary cell in the handoverprocedure, etc.). It may correspond to a frequency indicated as part ofthe radio resource connection configuration procedure. Some functionsmay be supported (e.g., only supported) on the PCell. For example, theUL CC of the PCell may correspond to the CC whose physical uplinkcontrol channel resources may be configured to carry HARQ ACK/NACKfeedback for a given WTRU.

For example, in LTE, the WTRU may use the PCell to derive the parametersfor the security functions and/or for upper layer system informationsuch as, but not limited to, NAS mobility information. Other functionsthat may be supported on (e.g., only on) the PCell DL include, but isnot limited to system information (SI) acquisition and change monitoringprocedures on the broadcast channel (BCCH), and paging.

“Secondary Cell (SCell)” may refer to the cell operating on a secondaryfrequency which may be configured once a radio resource controlconnection may be established and which may be used to provideadditional radio resources. System information relevant for operation inthe concerned SCell may be provided using, for example, dedicatedsignaling when the SCell may be added to the WTRU's configuration.Although the parameters may have different values than those broadcastedon the downlink of the concerned SCell using the system information (SI)signaling, this information may be referred to as SI of the concernedSCell and may be independent of the method used by the WTRU to acquirethe information.

“PCell DL” and “PCell UL” may refer the DL CC and the UL CC of thePCell, respectively. The terms “SCell DL” and “SCell UL” may correspondto the DL CC and the UL CC (if configured) of a SCell, respectively.

“Serving cell” may refer to a primary cell (e.g., a PCell) and/or asecondary cell (e.g., a SCell). For a WTRU that may or may not beconfigured with any SCell or that may or may not support operation onmultiple component carriers (e.g., carrier aggregation), there may beone (e.g., only one) serving cell comprised of the PCell. For a WTRUthat may be configured with at least one SCell, “serving cells” mayinclude, but are not limited to, the set of one or more cells comprisedof the PCell and configured SCell(s).

When a WTRU may be configured with at least one SCell, there may be one(e.g., always one) PCell DL and one PCell UL and, for each configuredSCell, there may be one SCell DL and one SCell UL (if configured).

It is contemplated that a WTRU may operate beyond the boundaries of thetypical bandwidth associated with a serving cell. It is alsocontemplated that the WTRU may operate on a frequency/carrier for whichit may or may not be used to decode some downlink signals according to atypical SCell operation. For example, the WTRU may handle configurationand/or activation/deactivation of additional bandwidth (e.g., eitherbandwidth used as an extension carrier or for carrier segments). Thismay include the determination of a center frequency (e.g., in case ofsymmetrical or asymmetrical extensions) and/or may includeactivation/deactivation of the additional bandwidth. The WTRU mayreceive downlink transmissions for the additional bandwidth, which mayinclude, for example, allocations of resources to the additionalbandwidth, downlink control signaling and downlink transmissions. Forexample, the additional bandwidth may be used in MBSFN subframes. Forexample, extension carrier may be synchronized (e.g., with or withoutPSS/SSS and/or CRS).

Although flexible bandwidth operations may be described using examplesbased on 3GPP LTE technology, it may be contemplated that such operationare applicable to other wireless technologies such as, but not limitedto, UMTS, HSPDA+, and/or WiMAX.

A WTRU may perform, for example, a procedure that includes at least oneof the following operations (e.g., to operate on additional bandwidth):(1) Configuration and Activation; (2) methods for DL transmission(including, but not limited to, RA for carrier segments and DCI formatdesign); (3) Methods for PDSCH decoding; (4) Carrier segments in MBSFNsubframes; (5) Synchronization for extension carriers/carrier segments;and/or (6) PUSCH transmission in carrier segments, among others. Detailsof such operations may be described below.

A WTRU may be configured to use carrier segments for a serving cell.Carrier segments may be configured for the downlink component carrierand/or for the uplink component carrier of the concerned serving cell.

A minimal set of configuration parameters for CSs (e.g., Lite CSsConfiguration) may be described herein. The WTRU may receive aconfiguration that may include parameters used to, for example, definethe extension of the nominal bandwidth B₀ that may be used by the WTRUfor the concerned serving cell, such that the WTRU may, for example,derive the value for total bandwidth B. For example, such parameters mayinclude a parameter B_(u), representing the bandwidth of one segment ofthe configured carrier segments and a parameter B_(d), representing thebandwidth of the other segment where B_(u)=B_(d) in case of asymmetrical extension (in which case a single parameter may be used) ofthe nominal bandwidth B₀.

The WTRU may adjust the RF front end to the center frequency of thetotal bandwidth B and may adjust the bandwidth of its transceiver to thetotal bandwidth B upon configuration of the carrier segments. Forexample, the eNB may provide for the WTRU a new center frequency for theextended carrier via higher layer signaling, once the WTRU may beconfigured with carrier segment for the concerned serving cell, forexample, when the initial state of whether or not the carrier segmentsmay be used is a deactivated state. If carrier segment activation anddeactivation is used, the WTRU may not retune its RF front end, forexample, for downlink transmission. For example, the WTRU may adjust,tune, and/or retune its RF front end when the carrier segments areactivated and/or deactivated. For uplink transmissions, the WTRU may beused to adjust its transmission emission mask at any change of the totalbandwidth B.

Carrier segments may be used for contiguous resource allocation ornon-contiguous allocation. Whether or not carrier segments may be usedfor contiguous allocation may be configurable for a given WTRU. Forexample, the resource allocation may differ based on the WTRU and/or thenetwork configuration (e.g., the configuration aspect). For example, ina subframe for which carrier segments may be used, the WTRU may performone of the following: (1) if a contiguous allocation is configurable,the WTRU may determine that the resource allocation (e.g., implicitly)extend beyond the edge of the indicated resource allocation. A guardband between the carrier segments and the concerned serving cell may notbe used. Resources (e.g., RBs) for data transmission may be allocatedcontiguously beyond the edges of the serving cell; or (2) if anon-contiguous allocation is configurable, the WTRU may determine thatthe resource allocation (e.g., implicitly) includes the physicalresource blocks of the carrier segments, for example, resource blocks(e.g., all RBs) of the concerned carrier segment. Some guard band(s) maybe used between the carrier segments and the concerned serving cell fornon-contiguous resource allocation. The size of guard band(s) used fornon-contiguous allocation may be signaled (e.g., in terms of number ofRBs) to the WTRU configured with the carrier segments via higher layersignaling. For example, the size of guard band(s) may be predefineddepending on the bandwidth of the serving cell and/or the bandwidth ofthe carrier segments.

The concerned resource blocks (e.g., nominal RBs and extended RBs) maybe concatenated according to any of the methods described herein

Control signaling for resource allocation may be flexible (e.g.,dynamic) by relying on physical layer signaling (e.g., PDCCH and/or DCIformat extensions) or may rely on at least a number of semi-staticallyconfigured parameters (e.g., by RRC configuration).

For example, the DCI format used for resource allocation may extend theR10 control signaling, (e.g., the WTRU may implicitly determine whetheror not it may decode downlink assignments (or transmit for uplinkgrants) for the concerned cell in the given subframe. For example, fordownlink transmissions the WTRU may use a configuration to determinewhether or not additional RBs may be used (and/or may be concatenated)with the downlink RB assignment for PDSCH indicated in the received DCI.For example, for uplink transmissions the WTRU may use a configurationto determine whether or not additional RBs may be used (and/or may beconcatenated) with the granted uplink RB resources for PUSCH indicatedin the received DCI.

The WTRU may receive a configuration that includes, in addition to theminimal set of configuration parameters used to determine RBs that maybe used for carrier segments, parameters that allow the WTRU to receive(or transmit) using one or more of the concerned RBs. The concernedconfiguration may include one or more semi-static resource allocations.For downlink transmissions, such parameter(s) may allow the WTRU toreceive and/or decode one or more of the concerned RBs for PDSCH and mayinclude, for example, the set of RBs (e.g., RB allocation) and/or aPDSCH transmission periodicity (or subframe configuration) for thecarrier segments. For uplink transmissions, such parameter(s) may allowthe WTRU to transmit using one of more of the concerned RBs for PUSCHand may include (e.g., the set of RBs (e.g., RB allocation) and a PUSCHtransmission periodicity (or subframe configuration) for the carriersegments. It is contemplated that the carrier segments may use the sameMCS and HARQ process as that of the concerned serving cell, but otherMCS and HARQ processes are possible. The configuration may includeparameters for reference signals (e.g., DM-RS) for downlinktransmissions and/or parameters for SRS extensions for uplinktransmissions.

The WTRU may apply the configured semi-static resource allocation in(e.g., only in) subframes for which the WTRU receives explicit controlsignaling (e.g., dynamic scheduling using PDCCH) for a downlinkassignment on PDSCH or in the subframe in which the granted uplinkresources may be used for a transmission on PUSCH.

The WTRU may apply the configured semi-static resource allocation to(e.g., only to) specific subframe(s), according to one or more of thefollowing: (1) the resource allocation may be available periodically,for example, starting from the subframe in which the activation commandis received by the WTRU; and/or the resource allocation may be availablefor a subset of subframes within a given set of subframes (e.g., duringa 10 ms frame).

For example, the WTRU may apply the configured semi-static resourceallocation in a subframe for which it has a configured downlinkassignment and/or a configured uplink grant (e.g., in the case ofresource allocation using semi-persistent scheduling). For example, theWTRU may receive a configuration for a semi-static resource allocationapplicable to a subset of the RBs of the carrier segment for a concernedserving cell using RRC signaling. The WTRU may receive a downlinkassignment for a PDSCH transmission in a DCI message on PDCCH (e.g.,cross-carrier scheduled) in a given subframe in which the semi-staticconfiguration of RBs for the carrier segment is applicable. The WTRU mayconcatenate the RBs indicated in the received DCI with the RBs indicatedby the semi-static resource allocation for carrier segments. The WTRUmay decode the PDSCH transmission using the RBs that result from aconcatenation process. For example, the WTRU may perform theconcatenation procedure if (e.g., only if) the use of carrier segment isactivated.

Legacy control signaling for downlink assignments and uplink grants maybe used in conjunction with carrier segments, for example, withoutmodifications to legacy DCI formats and/or blind decodingimplementations for PDCCH reception.

For example, a semi-static resource allocation configured for thecarrier segment for the WTRU may be disabled using RRC signaling and/orL1 signaling where the L1 signaling may be done (dynamically), forexample, using a single bit flag/field in a DCI message on PDCCH in agiven subframe in which the semi-static configuration of RBs for thecarrier segment is applicable. If it is disabled in the subframe, thenthe WTRU may be expected not to decode any data symbol in the PRBscorresponding to the semi-static resource allocation for the carriersegment. For this disabling (and/or enabling) of a semi-static resourceallocation for the carrier segment, a single bit may be defined in acorresponding DCI format. An implicit indication of the disabling(and/or enabling) may be done using an existing bit(s) (or anycombination of some of the existing bits/fields) in a DCI format.

For example, the configuration for semi-static resource allocation mayinclude a plurality of resource allocations, for example one or moresets of resource allocation. For example, a set may include up to ngroups of consecutive RBs allocated in the carrier segment. For example,a group may include a plurality of RB groups, for example, one group ofRBs in the carrier segment corresponding to extension B_(u) and anotherin extension B_(d). If a contiguous resource allocation is configurable,the WTRU may determine whether the RBs of the carrier segment correspondto extension B_(u) or to extension B_(d), by selecting the extensionwhich corresponding RBs may be adjacent to the allocated RBs in thereceived DCI format (or in the configured assignment or grant). Eachitem in the set of resource allocations may be indexed, for example,using an index allocation [0, n].

The WTRU may receive in the control signaling for the dynamic schedulingof a codeword (e.g., DCI on PDCCH) in a given subframe an indication ofwhat set of resource allocation it may use for the carrier segment and,for example, using a 2^(k) bit field in the case of up to k sets ofresource allocation. For example, when (e.g., only when) the use ofcarrier segment may be activated (e.g., according to at least one of themethods described herein). The WTRU may use the semi-static allocatedresource for the carrier segments. For example, the WTRU may use theresource allocation indicated in the activation command.

The WTRU may receive control signaling that activates the use of carriersegments for one of more serving cells of the WTRU's configuration.

The control signaling may include one or more of the following:

Layer 1 signaling: The WTRU may receive a DCI format on PDCCH thatindicates activation of a configuration for one or more carriersegment(s). For example, the indication may be according to at least oneof the following: (a) the WTRU may decode the DCI format using aconfigured RNTI (e.g., a CS-RNTI); and/or (b) the WTRU may determinethat a DCI format may be of a certain type and/or may include anexplicit indication (e.g., a field and/or flag). For example, the methoddescribed above used as an indication may activate and/or change theactivation state for the carrier segment of the carrier to which the DCIformat may be applicable (e.g., the serving cell corresponding to theconcerned PDCCH or the serving cell explicitly indicated by the carrierfield indicator in the DCI format). The WTRU may transmit a HARQ ACKfeedback to acknowledge the reception of the DCI interpreted as theactivation command. For example, for DCI signaling received in subframen, the WTRU may transmit HARQ ACK on an uplink channel in subframe n+k,where k may represent a WTRU processing delay (e.g., k=4 subframes).

Layer 2 signaling: The WTRU may receive a MAC Control Element (CE) thatindicates activation of a configuration for one or more carriersegment(s). For example, the MAC CE may be received on the PDSCH of anyserving cell of the WTRU's configuration. The WTRU may activate thecarrier segment(s) corresponding to the component carrier (e.g., uplinkor downlink carrier independently) and/or the serving cell (e.g., forone or both of the downlink and/or uplink component carriers, ifconfigured) based on an explicit indication (e.g., a bitmap, or aservingCellId) included in the MAC CE. The WTRU may activate the carriersegment(s) corresponding to the component carrier and/or the servingcell that it determines based on the identity of the serving cell onwhich PDSCH the MAC CE had been received. For example, the MAC CE mayinclude a configuration of the resource allocation to use for thecorresponding carrier segment(s).

Layer 3 signaling: The WTRU may receive a configuration for one or morecarrier segment(s), upon which the concerned segment may be activated.The configuration of the carrier segment may be included in the resourceconfiguration for a given serving cell.

Any of the methods described herein may include an indication of a setof resource allocations from the WTRU's configuration for the concernedcell it may use for the carrier segment after activation, for example,using a 2^(k) bit field in case of up to k sets of resource allocation.

The activation of the use of the carrier segments may be applied after afixed delay of, for example, k subframes. For example, for Layer 1signaling received at subframe n, the WTRU may start using the carriersegment in subframe n+k, where k may be equal to 8 subframes. For MAC CEsignaling received subframe n, the WTRU may start using the carriersegment in subframe n+k, where k may be equal to 8 subframes or, forexample, in the subframe after the transmission of a HARQ ACK for thetransport block in which the MAC CE was received. The WTRU may delay thestart of the use of the carrier segments for a given ongoing HARQprocess until the HARQ process successfully completes and/or until thecontrol signaling received indicates a new data transmission (e.g., fromthe New Data Indicator—NDI field in the DCI format).

When the WTRU receives control signaling that activates one or morecarrier segment for a given serving cell, the WTRU may perform at leastone of the following: (1) for a HARQ process for which a carrier segmentmay be used (e.g., UL and/or DL), the WTRU may consider the firstassignment for the corresponding HARQ buffer subsequent to the subframein which the activation state may change as a new transmission; and/or(2) for an uplink carrier segment, if configured, the WTRU may trigger aPower Headroom Report (PHR) for at least the concerned serving cell.

For example, the WTRU may perform any (or at least part) of the above inthe subframe in which the WTRU receives control signaling. For example,the WTRU may perform at least part of the above in the subframe in whichthe WTRU starts using the carrier segment (e.g., in the subframe of theactivation). The WTRU may perform (e.g., only perform) at least part ofthe above for control signaling that changes the activation state of thecarrier segment to the activated state.

While the WTRU uses carrier segments, the WTRU may perform at least oneof the following: (1) for control signaling that schedules radioresources, the WTRU may interpret a DCI applicable to the concernedserving cell according to a different format and/or syntax (e.g., forresource allocation when carrier segment may be used); (2) for anydownlink assignments, the WTRU may decode PDSCH, including methods toconcatenate the concerned RBs of the activated carrier segment(s); (3)the WTRU may use a CQI reporting method, if configured, that extends tothe carrier segments; and/or (4) the WTRU may change SRS reportingmethod, if configured, that extends to the carrier segments used foruplink transmissions (if configured).

The WTRU may receive control signaling that deactivates the use ofcarrier segments for one of more serving cells of the WTRU'sconfiguration.

The control signaling may include one or more of the following:

Layer 1 signaling: The WTRU may receive a DCI format on PDCCH thatindicates deactivation of a configuration for one or more carriersegment(s). The indication may be according to one or more of thefollowing: (a) The WTRU decodes the DCI format using a configured RNTI(e.g., a CS-RNTI); and/or (b) The WTRU determines that a DCI format maybe of a certain type and/or includes an explicit indication (e.g., afield and/or flag). The method above used as an indication maydeactivate and/or change the activation state for the carrier segment ofthe carrier to which the DCI format may be applicable (e.g., the servingcell corresponding to the concerned PDCCH or the serving cell explicitlyindicated by the carrier field indicator in the DCI format). The WTRUmay transmit a HARQ ACK feedback to acknowledge the reception of the DCIinterpreted as the deactivation command. For example, for DCI signalingreceived in subframe n, the WTRU may transmit HARQ ACK on an uplinkchannel in subframe n+k, where k may represent a WTRU processing delay(e.g., k=4 subframes).

Layer 2 signaling: The WTRU may receive a MAC Control Element (CE) thatindicates deactivation of a configuration for one or more carriersegment(s). The MAC CE may be received on the PDSCH of any serving cellof the WTRU's configuration. The WTRU may deactivate the carriersegment(s) corresponding to the component carrier (e.g., uplink ordownlink carrier independently) and/or the serving cell (e.g., for oneor both the downlink and/or uplink component carriers, if configured)based on an explicit indication (e.g., a bitmap, or a servingCellId)included in the MAC CE. The WTRU may deactivate the carrier segment(s)corresponding to the component carrier and/or the serving cell that itdetermines based on the identity of the serving cell on which PDSCH theMAC CE was received.

Layer 3 signaling: The WTRU may receive a configuration that modifiesand/or removes one or more carrier segment(s), upon which the concernedsegment may be deactivated. The WTRU may deactivate a carrier segmentaccording to one or more of the following: (1) the time since the lastscheduling for the concerned component carrier (or serving cell) if itmay be longer that a specific value (and may be configured). Forexample, a cs-DeactivationTimer may be used for each serving cell of theWTRU's configuration with configured carrier segments, and for example,for (e.g., only for) a downlink carrier segment; (2) for an uplinkcarrier segment, if configured, the Timing Advance for the concernedserving cell may no longer be valid (e.g., the Timing Alignment Timerhas expired); (3) the WTRU may receive control signaling that modifiesthe configuration of the carrier segment for the concerned serving cell;and/or (4) automatic deactivation of the carrier segments when thelinked carrier is deactivated.

When the WTRU receives control signaling that deactivates one or morecarrier segment for a given serving cell, the WTRU may perform at leastone of the following: (1) for a HARQ process for which a carrier segmentmay have been used (e.g., UL and/or DL), the WTRU may consider the firstassignment for the corresponding HARQ buffer subsequent to the subframein which the activation state changes as a new transmission; (2) for anuplink carrier segment, if configured, the WTRU may trigger a PowerHeadroom Report (PHR) for at least the concerned serving cell; and/or(3) the WTRU may revert to the configuration used in the nominalbandwidth for other procedures such as CQI reporting and/or SRStransmissions, if applicable.

Similar delay, as the delay associated with the activation, may beapplied for the deactivation of carrier segments, and for example, for adeactivation using explicit signaling.

Similar or identical to carrier segments, the eNB may activate ordeactivate an extension carrier for a given WTRU configured with theextension carrier. Several aspects may be considered as follows: (1) Fora given WTRU configured with an extension carrier,activation/deactivation of the extension carrier may be independent ofthe status of activation/deactivation of the serving cell associatedwith the extension carrier. For example, if the associated serving cellis deactivated, but not for the extension carrier, then the WTRU may beconfigured for the extension carrier to have another activated servingcell linked to it. The PCell may automatically become the associatedserving cell for the extension carrier. (2) Activation/deactivation ofthe extension carrier may be directly linked to theactivation/deactivation status of the serving cell. For example, anextension carrier may be deactivated when the associated serving cellbecomes deactivated.

Configuration of extension carriers may be restricted without CRS. Ifthe CRS is not transmitted on an extension carrier, the WTRU configuredfor the extension carrier may be configured, for example, intransmission mode (TM) 9 or a new TM for R11 and beyond. CSI-RS (or anewly defined RS) may be used for CSI measurement by the WTRU for theextension carrier.

Scheduling with CSs may be described herein. By using control signalingon, for example, the PDCCH to address PRBs in the extended bandwidth,carrier segments may be managed. For example, when carrier segments areactivated, a WTRU may use different, smallest PRB ranges (e.g., notexceeding 110 RBs in total) for such control signaling and/or scaling ofvalues may be used. Scaling may be defined as follows. Separate resourceallocation for carrier segments may be provided. Resource allocation fora carrier segment(s) may be done separately from the linked servingcell. Signaling RA for carrier segments in the same PDCCH as for thelinked BC CC may be used to define a new DCI format and/or signaling RAfor carrier segments in a different PDCCH may define a new DCI format.Joint resource allocation may be used. Resource allocation for the partof carrier segment(s) may be done jointly with that for the linked BCCC. DCI signaling in a single PDCCH may be used to provide a new DCIformat.

Resource block group size (P) may be defined as a function of bandwidth(e.g., the bandwidth of the component carrier B₀). For example, P may bea function of B₀ to ensure a smooth coexistence in the same subframeamong other UEs. If P is small (e.g., BC BW, B₀ is small) and carriersegment BW (e.g., B_(seg)=B_(U)+B_(D)) is large, the RA bits for B maybe larger than the maximum number of bits for RA.

P₁ may be a function of B₀ and P₂ may be a function ofB_(seg)=B_(U)+B_(D). P₁ may be used for B₀ and P₂ for B_(seg).

P may be a function of B (=B0+Bu+B1), which, for example, may notguarantee a smooth coexistence in the same subframe among other UEs(e.g., R-10 UEs), which may use P based on B₀.

P₁ may be a function of B₀, P₂ may be a function of B_(D), and P₃ may bea function of B_(U). P₁ may be used for B₀, P₂ for B_(D), and/or P₃ forB_(U).

Carrier segments may use different RA types from RA types used for B₀ ofthe linked BC CC. For example, type 0 or type 1 for B₀ and type 2localized RA for carrier segments B_(D) and B_(U).

DCI format(s) supported for carrier segments may be defined (e.g., PDCCHdesign for carrier segments). One or more of the existing DCI formatsmay be reused. For example, the respective DCI format may be modified,if appropriate, and/or DCI formats that may support carrier segments maybe specified. A new DCI format (e.g., including DCI size) may bedefined. A WTRU procedure for PDCCH decoding for carrier segments may bespecified. For example, DCI formats may include control information forcarrier segments that may be transmitted (e.g., only transmitted) in theWTRU specific SS.

Downlink resource allocation with carrier segments may be describedherein. When a WTRU may be configured with one or more carriersegment(s) for a given legacy cell, the resource mapping/allocation withcarrier segments may be specified as part of PDSCH/PUSCH transmissionand/or reception (e.g., including DCI signaling/receiving). For example,in R10, resource allocation (RA) type 0, type 1, and type2 may bedefined in order to allocate frequency resources (e.g., RBs) to eachscheduled WTRU according to different scheduling situations for eachWTRU, such as but not limited to the channel condition, data rate,and/or DCI format/TM configuration.

Parameters used in the respective RA type may be a function of thesystem bandwidth of a serving cell (or component carrier) of interest.For example, in RA of type 0/1, the size of the resource block group(RBG) P, which may be a function of the system BW, may be used to groupP-consecutive RBs to represent a RBG in the bitmap. When carriersegments are configured (e.g., the system bandwidth increases), P mayincrease to allocate resources for larger BW. The increase of P maycause inconsistency in resource allocation between the legacy WTRU(e.g., configured with the legacy BW) and the R-11 WTRU (e.g.,configured with the extended BW).

The following criteria may address provisioning of resource allocation(RA) associated with carrier segments. Backward compatibility to legacyWTRUs may be addressed. For example, P may be used (e.g., selected)based on system bandwidth (e.g., B₀) and RA algorithms (e.g., R-10 RAalgorithms) may be used. The RA algorithms may or may not be modified.The size of RA bits for type 0 and type1 may be used as defined in R-10,but other sizes are possible. The RA type 2 RA may ensure a smoothcoexistence in the same subframe between type 0 and type 1 (e.g., the RBgap values for the distributed type may be integer multiples of thesquare of the RBG size (e.g., NP²)). The B_(D) and B_(U) may be used byR-11 WTRUs.

The RBG size P may be selected based on system BW B₀ for backwardscompatibility. For example, the bitmaps of downlink resource allocationtype 0 and type 1, respectively, may be extended with carrier segments.Several methods for ordering concatenation of B₀, B_(U) and B_(D) may beconsidered.

RBs may be concatenated in the order of B₀, B_(U) and B_(D) (e.g.,B=B₀+B_(U)+B_(D) or B=B₀+B_(D) if B_(U) is not assigned). For example,if either of B_(D) or B_(U) is not assigned, its RBGs (N_(RBG)) may bezero.

For RA type 0, the total number of RBGs (N_(RBG))/bits for the bitmapmay be given by:N _(RBG) =└N _(RB,B) ^(DL) /P┘If the number of RBs of the legacy BW B₀ is not an integer multiple ofP, the last RBG of B₀ may include the first N_(first,B) _(U) P└N_(RB,B)₀ /P┘−N_(RB,B) ₀ ^(DL), but there may not be effects on legacy WTRUs(e.g., it is backwards compatible).

The corresponding resource allocation fields may be illustrated below:

Example Resource Allocation Fields for RA Type 0 Type Bitmap: N_(RBG)for B (=B₀ + B_(U) + B_(D) or = B₀ + B_(D))

For RA type 1, the total RBs of the bitmap used to address VRBs in aselected RBG subset may have size N_(RB) and may be defined by:N _(RB) =└N ^(RB,B) ^(DL) /P┘−└ log₂ P┘−1The bitmap and shift of each subset may be constructed based on B byusing the same algorithms of, for example, R-8. The correspondingresource allocation fields may be illustrated below:

Example Resource Allocation Fields for RA Type 1 Type Subset Shift for BBitmap: N_(RB) for B (=B₀ + B_(U) + B_(D))

RBG's may be concatenated in the order of B_(D) and B_(0U) (=B₀+B_(U)).B_(0U) may indicate BW concatenated with B₀ and B_(U). If the number ofRBGs for B_(D), N_(RBG,1), is not an integer multiple of P, null RBs ofN_(nulls) may be inserted in the last RBG of B_(D) where PN_(nulls)=P└N_(RB,B) _(D) ^(DL)/P┘−RB,B_(D) ^(DL), and ignored whenactual data may be mapped into the RBs. If the number of RBGs forB_(0U), N_(RBG,2), is not an integer multiple of P, null RBs ofN_(nulls) may be inserted in the last RBG of B_(0U) whereN_(nulls)=P└N_(RB,B) _(0U) /P┘−N_(RB,B) _(0U) ^(DL), and ignored whenactual data may be mapped into the RBs.

For example, if a number of RBGs of a carrier segment is not an integermultiple of the size of the RBGs, then a number of null RBs may beinserted into a last RBG of the carrier segment such that the number ofnull RBs plus the number of RBs of the second carrier segment isdivisible by the size of the RBGs. The number of null RBs may bevariable.

For RA type 0, the number of bits/RBGs for the bitmap may be calculatedrespectively for B_(D) and B_(0U) as set forth in:N _(RBG,1) =└N _(RB,B) _(D) ^(DL) /P┘,N _(RBG,2) =└N _(RB,B) _(D) ^(DL) /P┘and/or concatenated in the order of B_(D) and B_(0U). The correspondingresource allocation fields may be illustrated below:

Example Resource Allocation Fields for RA Type 0 Type Bitmap: N_(RBG, 1)Bitmap: N_(RBG, 2) for B_(D) for (B₀ + B_(U))

At least two bitmaps may be associated with resource allocationinformation. For example, the resource allocation information maycomprise two bitmaps. A first bitmap may be associated with the RBGs ofthe component carrier and the RBGs of a first carrier segment and asecond bitmap may be associated with the RBGs of a second carriersegment. The number of bits/RBG for the first bitmap may be equal to thenumber of RBs in the component carrier and first carrier segmentcombined divided by the size of a RBG. The number of bits/RBG for thesecond bitmap may be equal to the number of RB in the second carriersegment divided by the size of a RBG.

For RA type 1, one shift bit may control shifting operation for thesubsets of one or more of B_(D) and B_(0U) (e.g., simultaneously). Thenumber of bits/RBs for the bitmap may be calculated as set forth in:N _(RB) =└N _(RB,B) _(D) ^(DL) /P┘−(└N _(RB,B) _(0U) ^(DL) /P┘−└ log₂P┘−1)

The corresponding resource allocation fields may be illustrated below:

Example Resource Allocation Fields for RA Type 1 Type Subset ShiftBitmap: N_(RB)One shift bit may be used for B_(D) and another shift bit for B_(0U).The number of bits/RBs for the bitmap may be calculated as set forth in:N _(RBG,1) =└N _(RB,B) _(D) ^(DL) /P┘−1N _(RBG,2) =└N _(RB,B) _(0U) ^(DL) /P┘−└ log₂ P┘−1

The corresponding resource allocation fields may be illustrated below:

Example Resource Allocation Fields for RA Type 1 Type Subset Shift forB_(D) Shift for B_(0U) Bitmap: N_(RB) = N_(RB, 1) + N_(RB, 2)

The corresponding resource allocation fields may be rearranged as shownbelow:

Example Rearranged Resource Allocation Fields Type Subset Shift forBitmap: Shift for Bitmap: N_(RBG, 2) B_(D) N_(RBG, 1) B_(0U) Type SubsetShift for Bitmap: Shift for Bitmap: N_(RBG, 1) B_(0U) N_(RBG, 2) B_(D)

RBGs may be concatenated in the order of B_(D), B₀, and B_(U). For RAtype 0, the number of bits/RBGs for the bitmap may be calculated as setforth in:N _(RBG,1) =└N _(RB,B) _(D) ^(DL) /P┘,N _(RBG,2) =└N _(RB,B) ₀ ^(DL) /P┘,N _(RBG,3) =└N _(RB,B) _(U) ^(DL) /P┘and/or concatenated in the order of B_(D), B₀, and B_(U). If N_(RBG,1)for B_(D) is not an integer multiple of P, then null RBs (N_(null)) maybe inserted in the last RBG of B_(D), where N_(nulls)=P└N_(RB,B) _(D)^(DL)/P┘−N_(RB,B) _(D) ^(DL) for B_(D), and ignored when actual data maybe mapped into RBs. Likewise null RBs may be inserted for B₀ and B_(U)respectively. The corresponding resource allocation fields may beillustrated below:

Example Resource Allocation Fields for RA Type 0 Type Bitmap: N_(RBG, 1)Bitmap: N_(RBG, 2) Bitmap: N_(RBG, 3) for B_(D) for B₀ for B_(U)

For example, the resource allocation information may comprise threebitmaps. A first bitmap may be associated with the RBGs of the componentcarrier, a second bitmap may be associated with the RBGs of a firstcarrier segment, and a third bitmap may be associated with the RBGs of asecond carrier segment. The number of bits/RBG for the first bitmap, thesecond bitmap, and the third bitmap may be the number of RBs in therespective carrier divided by the size of the RBG.

For example, if the number of RBGs of the component carrier, the firstcarrier segment, and/or the second carrier segment is not an integermultiple of the size of the RBGs, then a number of null RBs may beinserted into the last RBG of the respective carrier such that thenumber of null RBs plus the number of RBs of the respective carrier isdivisible by the size of the RBGs.

For RA type 1, one shift bit may control shifting operation for Psubsets for B_(D), B₀, and/or B_(U) (e.g., simultaneously) (e.g., allsubsets may use their own shifted bitmaps, respectively), if the shiftbit may be set. The number of bits/RBs for the bitmap may be calculatedset forth in:N _(RB,1) =└N _(RB,B) _(D) ^(DL) /P┘,N _(RB,2) =└N _(RB,B) ₀ ^(DL) /P┘−└ log₂ P┘−1,N _(RB,3) =└N _(RB,B) _(U) ^(DL) /P┘,

The corresponding resource allocation fields may be illustrated below:

Example Resource Allocation Fields for RA Type 0 Type Subset ShiftBitmap: N_(RB, 1) Bitmap: N_(RB, 2) Bitmap: N_(RB, 3) for B_(D) for B₀for B_(U)

One shift bit per B_(D), B₀, B_(U) may be utilized (e.g., each subsetmay select its own shifted bitmap based on its own shift bit). Thenumber of bits/RBs for the bitmap may be calculated as set forth in:N _(RB,1) =└N _(RB,B) _(D) ^(DL) /P┘−1,N _(RB,2) =└N _(RB,B) ₀ ^(DL) /P┘−└ log₂ P┘−1,N _(RB,3) =└N _(RB,B) _(U) ^(DL) /P┘−1

The corresponding resource allocation fields may be illustrated below:

Example Resource Allocation Fields for RA Type 1 Type Subset Shift forShift for Shift for Bitmap: Bitmap: Bitmap: B_(D) B₀ B_(U) N_(RB, 1)forN_(RB, 2) for N_(RB, 3) for B_(D) B₀ B_(U)

The resource allocation fields may be rearranged as shown:

Example Rearranged Resource Allocation Fields Type Subset Shift forBitmap: Shift for Bitmap: Shift for Bitmap: B_(D) N_(RB, 1) B₀ N_(RB, 2)for B_(U) N_(RB, 3) for for B_(D) B₀ B_(U)

Examples of methods that may be used for RA type 2 with carrier segmentsmay be described herein.

For a localized RA, the method of R-10 uplink RA type 0 or type 1 may beextended with one or more of the following modifications. RB indexordering may be constructed based on the following concatenationordering:N _(RB,B) ^(DL) =N _(RB,B) ₀ ^(DL) +N _(RB,B) _(U) ^(DL) +N _(RB,B) _(D)^(DL)

concatenated in the order of B₀, B_(U) and B_(D).

The order may be changed, for example, to N_(RB,B) ^(DL)=N_(RB,B) _(D)^(DL)+N_(RB,B) ₀ ^(DL)+N_(RB,B) _(U) ^(DL) concatenate in the order ofB_(D), B₀ and B_(U).

The order may be based on the legacy part (e.g., B₀) and the segmentpart B_(D), B_(U) (e.g., separately/individually), for example, N_(RB,B)₀ ^(DL), N_(RB,B) _(D) ^(DL), N_(RB,B) _(U) ^(DL).

The order may be based on the legacy part (B₀) part and a segment part(B_(D)+B_(U), or B_(U)−B_(D))) separately (e.g., and N_(RB,B) ₀ ^(DL)and (N_(RB,B) _(D) _(−B) _(U) ^(DL) or N_(RB,B) _(U) _(−B) _(C) ^(DL))).

For example, for uplink RA type 1 method, the number of RA sets M andthe RBG size P may be predetermined with respect to concatenated BWsabove. For example, P may be selected based on B₀, or B₀ and eachsegment BW B_(D), B_(U), or B_(D)+B_(U). M and P may be signaleddynamically by PDCCH or semi-statically via L2/L3 signaling.

For Distributed RA, the operations may be as follows. Interleaveroperation may apply to: (i) total BW B; (ii) legacy BW B₀; (iii) B₀ andB_(U)+B_(D) (or B_(D)+B_(U)) separately and then stack them to read outcolumn by column; and/or (iv) B_(D), B₀ and B_(U) separately and thenstack them to read out column by column. Frequency hopping for odd timeslots to: (i) disable (e.g., always disable) for carrier segments and/orenable/disable (e.g., always enable/disable) by L1 signaling; (ii) applyto B₀ (e.g., the same as R-10); (iii) apply to B_(D), B₀, B_(U), B_(UD)(e.g., independently); and/or (iv) apply to B by redesigning Gap tablefor B.

The RBG size P′ may be an integer multiple of P (P′=NP) where P may beselected based on system BW B₀ where N=└N_(RB,B) ^(DL)/N_(RB,B) ₀ ^(DL)┘(e.g., if B_(D)+B_(U)<=B₀, then P′=2P).

This may be used, for example, in cases that the maximum size of RA bitsfor Type 0 and Type 1 for N_(RB,B) ^(DL) may be out of range for a givenP, for example, as illustrated in Table 4 and/or the number of blinddecodes (e.g., payload sizes) with carrier segments may be kept the sameas that of R-8 and/or R-10 (e.g., to match the payload size of R-8and/or R-10 DCI formats some padding bits may to be added, ifappropriate).

TABLE 4 System RBG Max. Bits for Bandwidth Size (P) Type 0 and Type 1≤10 1 10 11-26 2 13 27-63 3 21  64-110 4 28

For example, the size of a RBG of a component carrier and at least onecarrier segment may be based on a scaling factor multiplied by a legacyRBG size (e.g., 3GPP Rel-8/Rel-10 RBG size) of the component carrier.The legacy RBG size may be determined by the system bandwidth of thecomponent carrier. For example, the legacy RBG size may be determined byapplying the system bandwidth of the component carrier to Table 4described herein. The scaling factor may be determined by the number(e.g., maximum number) of RBs of the component carrier and the one ormore carrier segments. For example, if the combined number of RBs of theone or more carrier segments is less than or equal to the number of RBsof the component carrier, then the scaling factor may be two. If thecombined number of RBs of the one or more carrier segments is greaterthan the number of RBs of the component carrier, then the scaling factormay be x, wherein x is equal to the combined number of RBs of thecomponent carrier and the one or more carrier segments divided by thenumber of RBs of the component carrier.

For example, N RBs may be grouped to create an element of RBG. Examplesmay be provided herein for P′=NP where N=2. An element of RBG may beconstructed with two (N=2) consecutive RBs (e.g., [(0,1),(2,3)],[(3,4),(5,6)], . . . ). An element of RBG may be constructed with a RBand its 4^(th) (NP-th) RB (e.g., [(0,4),(1,5)], [(2,6),(3,7)],[(8,12),(9,13)], [(10,14),(11,15)], . . . ). The same R-10 RA algorithmwith newly constructed RBGs above may be applied. The gap for Type 2 maybe an integer multiple of NP² in order to ensure a smooth coexistence inthe same subframe between other types (0, 1).

FIGS. 7 to 13 are diagram illustrating example bitmaps.

Referring the FIG. 7 , the example bitmap is based on P′=2P (N=2, P=2based on B₀=25 RBs, segment BW=10 RBs) where:N _(RB,B) ^(DL)=25+10=35, P′=2P=2×2=4, N _(subset)=log₂ P or N_(subset)=log₂(2P)

For Type 0, the number of bits for the bitmap may be derived by:N _(RBG) =└N _(RB,B) ^(DL) /P′┘

For example, the resource allocation information may be associated witha bitmap. The number of bits for the bitmap may be determined by acombined number of RBs of the component carrier and the one or morecarrier segments divided by the size of a RBG.

Referring to FIG. 8 , an example bit map is shown.

For Type 1, the number of bits for the bitmap may be derived by:N _(RBs) =└N _(RB,B) ^(DL) /P′┘−└ log₂ P┘−1

Referring to FIGS. 9 and 10 , example bit maps for Type 1 are shown.

Referring to FIGS. 11 and 12 , example bit maps may be shown for Type 0,P′=2P and N_(RB) ^(DL)=50,P=3. The number of bits for bitmap may bederived byN _(RBG) =└N _(RB,B) ^(DL) /P′┘=9.

Referring to FIG. 13 , an example bit map, the element of which may be apair of RBs as described in type 0 above, is shown. The number of bitsfor the bitmap may be derived byN _(RBs) =└N _(RB,B) ^(DL) /P┘−└ log₂ P┘−1=6

RBG size P′ may be calculated as a function of the system BWs B₀ and Band P, for example: P′=└N_(RB,B) ^(DL)/N_(RBG) ₀ ┘, where N_(RBG) ₀=└N_(RB,B) ₀ ^(DL)/P┘.

For the resource allocation Type 0, for example, the number of bits fora bitmap may be derived byN _(RBG) =└N _(RB,B) ^(DL) /P′┘.

For the resource allocation Type 1, the number of the bits for bitmapmay be derived by N_(RB) ^(TYPE1)=└N_(RB,B) ^(DL)/P′┘−└ log₂ P′┘−1. Thenumber of bits for bitmap may be derived byN _(RB) ^(TYPE1) =└N _(RB,B) ^(DL) /P┘−└ log₂ P′┘−1.

The implementations described herein may be used, for example, when themaximum size of RA bits for Type 0 and Type 1 for N_(RB,B) ^(DL) may beout of range for a given P and/or the number of blind decodes (e.g.,payload sizes) and/or the bits used for bitmap with carrier segments maybe kept the same as that of Rel-10 (e.g., in order to match the payloadsize of Rel-10 DCI formats some padding bits may be added if necessary).The number of the bits for the resource allocation (e.g., required forthe resource allocation) of the whole carrier (e.g., including thesegments) with system bandwidth B may be equal to or less than that ofthe R-10 for system BW B₀. The new RBG may be selected to have theminimum possible size considering the number of available Rel-10resource allocation bits corresponding to P.

For example, the size of a RBG of a component carrier and at least onecarrier segment may be based on the combined number of RBs of thecomponent carrier and the one or more carrier segments divided by thenumber of legacy RBGs (e.g., 3GPP Rel-8 or Rel-10 RBGs) of the componentcarrier and rounding up the resulted value to the next highest wholenumber. The number of legacy RBGs may be determined by dividing thesystem bandwidth of the component carrier by the legacy RBG size (e.g.,3GPP Rel-8 or Rel-10 RBG size) and rounding up to the next highest wholenumber. For example, a legacy RBG size (e.g., 3GPP Rel-10 RBG size) ofthe component carrier may be determined by applying the system bandwidthof the component carrier to Table 4 described herein.

For example, new RB groups may be constructed. An element of a RBG maybe constructed with P′ consecutive RBs (e.g., for P′=3 the RBGs may be(0,1,2),(3,4,5), . . . ). An element of a RBG may be constructed with aRB and its P′-th RB (e.g., for P′=3 the RBGs may be(0,3,6),(1,4,7),(2,5,8),(9,12,15),(10,13,16), . . . ). The same Rel-10RA algorithm may be applied with newly designed P′ and its resulted RBGs(e.g., those described above).

For example, P′ may=3 (e.g., P=2 based on B₀=25 RBs, segment BW=10 RBs).N_(RB,B) ^(DL)=25+10=35, P=2, N_(RBG) ₀ =13, P′=└35/13┘=3.

In RA Type 0, the number of bits for a bitmap may be derived by, forexample, N_(RBG)=└N_(RB,B) ^(DL)/P′┘=12. FIG. 14 is a diagramillustrating an example bitmap.

For RA Type 1, for example, using N_(RB) ^(TYPE1)=└N_(RB,B) ^(DL)/P′┘−└log₂ P′┘−1, the number of the bits for bitmap may be N_(RB) ^(TYPE1)=9.FIG. 15 is a diagram illustrating an example of bit-mapping.

For example, P′ may=4 (e.g., P=3 based on B₀=28 RBs, segment BW=6+6 RBs)N_(RB,B) ^(DL)=28+6+6=40, P=3, N_(RBG) ₀ =10, P′=└40/10┘=4.

For RA Type 0, the number of bits for a bitmap may be derived byN_(RBB)=└N_(RB,B) ^(DL)/P′┘=10. FIG. 16 is a diagram illustrating anexample bitmap.

For RA Type 1, for example, using N_(RB) ^(TYPE1)=└N_(RB,B) ^(DL)/P′┘−└log₂ P′┘−1, the number of the bits for a bitmap may be N_(RB)^(TYPE1)=7. FIG. 17 is a diagram illustrating an example of bit-mapping.

Methods (e.g., composite methods) may use DL RA methods for a backwardscompatible part and/or UL RA method (Type 0 or Type 1) for carriersegment parts. The backwards compatible/legacy part (e.g., B₀) may useR-10 RA methods (e.g., no changes) and the carrier segment parts (e.g.,B_(D) and B_(U)) may use enhanced R-10 uplink methods with RA type 0 ortype 1 with M, where M may be the number of resource blocksets/clusters. M may be predetermined for each segment part or forcombined segment parts (e.g., M1 for B_(D) and M2 for B_(U), or M forB_(D)+B_(U), etc.). M may be signaled dynamically by PDCCH orsemi-statically via L2/L3 signaling.

The uplink resource allocation with carrier segments may use the samemethods for the downlink RA with carrier segments described herein, forexample, by disabling frequency hopping. The following frequency hoppingmethods may be used: disable (e.g., always disable) for carrier segmentsor enable/disable by L1 signaling; apply to B₀ (e.g., only apply) (e.g.,the same as R-10); apply R-10 frequency hopping method to B₀ andseparately hopping between B_(D) and B_(U); apply to B_(D), B₀, B_(U),B_(UD) independently; and/or apply to B by redesigning Gap table for B.

Separate DCI for carrier segments from the backward compatible PDCCH maybe described herein.

FIG. 18 is a diagram illustrating an example of a DCI transmission forCSs in PDSCH. Referring to FIG. 18 , since the RA methods, e.g., asdescribed herein, may be designed based on one jointly encoded PDCCHwith carrier segments, the payload sizes of DCI formats may increase.The number of blind decodes may increase due to new DCI formats, whichmay accommodate larger payload sizes for RA for carrier segments. Inorder to avoid growing blind decodes, the following may be implemented.

Partitioning DCI into two parts such that one part for legacy DCI/PDCCHmay reside on the legacy control region, e.g., as in R-10, and the otherpart for carrier segment DCI may be placed on an extended control regionof PDSCH. The extended control region of PDCCH for carrier segments maybe a part of resource blocks (or, e.g., resource elements (REs)) forPDSCH (or, e.g., the data field) corresponding to a WTRU such that eNBmay assign RBs (or, e.g., REs) for PDSCH including CCEs for carriersegment DCI, for example as shown in FIG. 18 .

Resource allocation methods for the extended control region of PDSCH forcarrier segment DCI may follow predetermined frequency first thentime/OFDM symbols. Resource allocation methods for the extended controlregion of PDSCH for carrier segment DCI may follow predeterminedtime/OFDM symbols first then frequency. Such implementations may includeone or more of the following options: with the lower region in allocatedRBs for PDSCH through OFDM symbols (e.g., all OFDM symbols); with thehigher region in allocated RBs for PDSCH through OFDM symbols (e.g., allOFDM symbols); with the center region in allocated RBs for PDSCH throughOFDM symbols (e.g., all OFDM symbols); and/or with a distribution ofboth low and high region to exploit frequency diversity. Resourceallocation methods for the extended control region of PDSCH for carriersegment DCI may follow predetermined distributed through a data blockusing predetermined rules (e.g., close to RS: CRS, DMRS, and/or CSI-RS).

In certain example embodiments, it may be signaled via a higher layer.In certain example embodiments, the resource allocation may be implicitand may use WTRU specific parameters. In certain example embodiments, itmay be signaled dynamically by PDCCH or semi-statically via L2/L3signaling.

As an extension carrier may be configured as an R-10 serving cell (e.g.,a SCell), the resource allocation methods used for a R-10 SCell may beapplied for extension carriers. An extension carrier may be configureddifferently as compared to an R-10 SCell, for example, with no CRS, noPDCCH, no PBCH, and/or no PSS/SSS transmission on the extension carrier.An extension specific resource allocation/mapping scheme may be used. IfPDCCH is not configured for an extension carrier, cross-carrierscheduling for the extension carrier may be performed by a linkedserving cell. A new DCI format or formats may be defined to supportextension carriers in, for example, R-11 and beyond for 3GPP.

Extension carriers may be configured within a small system bandwidth(e.g., less than 5 MHz) and DCI formats and/or resource allocations withfull flexibility in resource block (RB) assignment may not beappropriate. For example, as RA type 2 (e.g., as defined in resourceallocation for PDSCH in LTE-A) may be associated with a relatively smallPDCCH payload size, RA type 2 may support extension carriers (e.g., onlyRA type 2). Other resource allocation type (e.g., RA type 0 or 1 definedin LTE-A DL) may be applied for extension carriers.

The RA scheme used for LTE-A PUSCH transmission may be used forextension carriers where a localized type RA method is defined forPUSCH. For example, resource allocation type 0 or type 1, which isdefined in R-10 DCI format 0/4, may be applied for extension carriers.

Frequency hopping may be applied to extension carriers on a slot and/orresource block basis.

The PDSCH may be mapped to physical resources in the extended bandwidth(e.g., mapping to REs within carrier segments). When carrier segmentsare configured for a serving cell, the PRBs may be numbered in thecarrier segments. The following rules may be considered for RB/REmapping with carrier segments: Maintain PRB numbers within a main (R-10)carrier as in R-10 (e.g., numbering PRBs starting at the lowestfrequency of the main carrier); Extend PRB numbers for carrier segmentsin a consecutive manner, if possible; and/or Avoid changing the R-10 RSRE mapping rule, if any, due to numbering PRBs in carrier segments.

FIGS. 19 and 20 are diagrams illustrating examples of numbering PRBswith carrier segments. Several variations may exist for numbering PRBsin carrier segments. FIG. 19 shows one example of such a process. Asshown in the FIG. 19 , the PRBs in the main carrier may be numberedfirst, then the upper carrier segment may be numbered following thelower carrier segment (e.g., with wrapping around). FIG. 20 showsanother example numbering process. As shown in the FIG. 20 , consecutivenumbering for the overall carrier occurs. In this case, the RBs in thelower carrier segment may be numbered with negative values.

The PDSCH may be mapped to physical resources in the extended bandwidth(e.g., mapping to REs with carrier segments). This may be related toresource allocation for carrier segments including mapping from VRB toPRB in carrier segments.

Modulated data symbols may be mapped to REs/RBs first in the mainserving cell and then the rest of the modulated symbols may be mapped toREs/RBs in carrier segments. The mapping of modulated data symbols intoRBs may occur in ascending order of RB index numbers, for example,starting with the lowest RB index number (e.g., with an RB index ofzero). Because there may be no PBCH, no synchronization signals(PSS/SSS) and/or no CRS in the carrier segments, Res (e.g., all Res)(e.g., except for DM-RS and possible CSI-RS) in the physical RBscorresponding to the VRBs assigned for PDSCH may be used for PDSCH inthe carrier segments.

Unused symbols of the control region in carrier segments may bereclaimed (e.g. reused). The starting OFDM symbol for the PDSCHtransmission in carrier segments may be defined. For example, thestarting OFDM symbol for the PDSCH in the carrier segment may be thesame as of the linked serving cell. The starting symbol for the PDSCHmay be offset with regard to the starting OFDM symbol for the linkedserving cell. FIG. 21 is a diagram illustrating an example mapping ofPDSCH in carrier segments.

The carrier segments may have their own starting OFDM symbol within thecarrier segments. The starting OFDM symbol for the PDSCH in carriersegments may be given to the WTRU via higher layer signaling or L1signaling (e.g., using PCFICH). The particular symbol may be predefined(e.g., the first OFDM symbol), for example, during the configurationand/or activation of the carrier segments. The eNB may configure eachR11 WTRU between the implementations described herein via L1 (e.g.,dynamic) and/or L2/3 signaling (e.g., semi-static). FIG. 22 is a diagramillustrating an example mapping of PDSCH in carrier segments.

The PDSCH EPRE (Energy per RE) in carrier segments may be defined. ThePDSCH EPRE (Energy per RE) in carrier segments may include the same EPREas for the PDSCH on the linked BC CC. The WTRU may consider that thepower based on pB may be applied for the PRBs in the carrier segments.The Tx power (EPRE) of PDSCH in carrier segment may be different fromthat on the linked BC CC (e.g., for DL interferencecoordination/management). With different power allocations for thecarrier segments and the backwards compatible CC, the eNB may controlinterference (e.g., inter-cell interference) differently between thecarrier segments and the backwards compatible CC. The transmit powerlevels for different carrier segments may be different. If the transmitpower levels between the carrier segments and the linked CC aredifferent, then the power ratio (e.g., or power difference) may besignaled to the WTRU via, for example, broadcast signaling or dedicatedsignaling.

WTRU procedures for receiving PDSCH on extension carriers may bedescribed herein. An extension carrier may be configured as a SCell, butwithout some of the PHY channels/signals, for example, no PBCH, noPDCCH/PHICH/PCFICH, no PSS/SSS, and/or no CRS (e.g., in Rel11). A WTRUconfigured with an extension carrier may not be used to receive/processthe PHY channel(s)/signal(s) which may not be transmitted on theextension carrier. For example, if the (legacy) CRS is not present inthe extension carrier, the WTRU may not perform CRS based channelestimation for the extension carrier. In the absence of some of thecontrol/system information, the extension carrier may not be accessibleand/or backward compatible to UEs of a previous release.

Each extension carrier may be configured differently. Implementationsassociated with receiving PDSCH extension carriers may be describedherein.

Knowing the physical characteristics of an extension carrier may bediscussed herein (e.g., receiving a configuration for an extensioncarrier from the eNB). As an extension carrier may have differentcharacteristics than a legacy serving cell, any distinction may be madefor an extension by a WTRU configured for the extension carrier, so thatthe WTRU may receive PDSCH on the extension carrier. The WTRU may knowthe physical characteristics of an extension carrier configured for it.

For example, during RRC connection (re)configuration that adds a servingcell (e.g., using dedicated RRC signaling), the WTRU may be configuredwith an extension carrier (as a SCell) with (additional) extensioncarrier specific parameters. Such extension carrier specific parametersmay include any combination of the following: bandwidth of the extensioncarrier (e.g., in terms of number of RBs); CRS configuration (e.g.,presence or absence of CRS in the extension carrier), and CRS pattern,if CRS is present; and/or the number of antenna ports used for CRStransmission, if CRS is transmitted in the extension carrier. RRCconnection (re)configuration for an extension carrier may be done by thePCell or the serving cell linked to the extension carrier.

During RRC connection (re)configuration that adds a serving cell, aparameter in RRC signaling may indicate to the WTRU whether theconfigured carrier is an R-10 SCell or an R-11 SCell. Somecharacteristics (e.g., physical characteristics) may be predefinedand/or standardized for R-11 SCell (e.g., extension carriers), such asbut not limited to, no PSS/SSS, no PBCH, no PDCCH/PHICH/PCFICH and/or noCRS.

During RRC connection (re)configuration that adds a serving cell, theWTRU may derive/determine the carrier type of the configured servingcell, for example, by the cell ID (e.g., SCellID), the type of IE used(e.g., translating in one bit flag in ASN.1 according to standardpractice for ASN.1) and/or whether or not a given parameter is present,etc. For example, if a parameter x is present in the configuration ofthe SCell, then the WTRU may know that the configuration is for anR-11SCell (e.g., extension carrier).

A L1 indicator regarding the type of the carrier may be signaled to theWTRU, for example, in the PDCCH corresponding to the carrier. Forexample, a flag bit(s) indicating the type of the carrier may beincluded in the PDCCH for the concerned carrier.

Depending on the DCI format in PDCCH and/or transmission mode (TM) (orcombination of the DCI format and TM) used for the concerned carrier,the WTRU may identify/derive the type of the carrier. For example, ifthe WTRU is configured with TM x in the carrier and/or DCI format y forthe carrier, the WTRU may consider that the carrier is of a givencarrier type (e.g., extension carrier). A new DCI format(s) and/or a newTM(s) may be defined/supported for extension carriers.

Once the (e.g., R-11) WTRU knows about the type of the configuredcarrier (e.g., using one or a combination of the above embodiments), itmay perform some PHY functions (e.g., PHY procedures) with the carrier,accordingly, but may also avoid unnecessary operation(s). For example,if the WTRU is configured with an extension carrier not carrying PBCH,PSS/SSS, PDCCH, and/or CRS, then it may skip any operation(s) (e.g.,some PHY procedures) associated with the PHY channel(s)/signal(s) nottransmitted in the concerned carrier. If some control/system informationand/or measurement/synchronization information used for the concernedcarrier may not be available from the carrier due to the absence of somePHY channel(s)/signal(s), then the WTRU may obtain/acquire theinformation/parameter(s) from another carrier (e.g., PCell or the linkedcarrier).

Cross-carrier scheduling for extension carriers (e.g., in the case of noPDCCH in extension carrier) may be described herein. If PDCCH is notconfigured for an extension carrier, cross-carrier scheduling for theextension carrier may be performed by a linked serving cell. Inaddition, a new DCI format(s) may be supported for extension carriers inR-11 and beyond. In order to minimize any (negative) impact on the WTRUPDCCH decoding complexity, it may be advantageous to provide someconstraints on blind decoding of PDCCH for extension carriers.

When a WTRU is configured with an extension carrier(s), each extensioncarrier may have an associated legacy (e.g., backward compatible)carrier which may be configured for the WTRU. The association may beprovided for the WTRU (e.g., via RRC signaling) as part of theconfiguration information for the extension carrier. The legacy carriermay be associated with multiple extension carriers configured for theWTRU. The individual extension carrier may be cross-carrier scheduledwith the associated legacy carrier. For example, as in R-10, for a givenextension carrier, the CIF (carrier indicator field) in thecorresponding PDCCH transmitted on the associated legacy carrier may beused for supporting cross-carrier scheduling for the extension carrier.Each extension carrier configured for a WTRU may have a unique cell IDwhich may be the same CIF value for the extension carrier. A group ofextension carriers configured for a WTRU may have same cell ID.

An extension carrier specific RNTI may be assigned to each extensioncarrier and/or a group of extension carriers. A PDCCH for an extensioncarrier may have CRC bits scrambled with extension carrier specificRNTI. The WTRU configured with an extension carrier may perform blinddecoding of PDCCH for the extension carrier using the assigned RNTI.

In order to reduce the complexity of blind decoding of PDCCH for anextension carrier, the any combination of the following restrictions oncross-carrier scheduling for extension carriers may be specified.

For a given extension carrier, PDSCH transmission on the extensioncarrier may be cross-carrier scheduled from PDCCH on the associatedlegacy carrier (e.g., only on the associated legacy carrier).

A set (e.g., limited set) of reception type combinations and/ormonitored RNTI types may be used for extension carriers, for example, sothat a WTRU configured with an extension carrier may monitor the set ofPDCCH candidates on the associated legacy carrier. For example, anextension carrier configured for a WTRU may transmit (e.g., onlytransmit) dynamically scheduled unicast data, so that, for example, theextension carrier the WTRU may monitor PDCCH with CRC scrambled byC-RNTI (e.g., in the WTRU specific search space of the associated legacyWTRU). A WTRU configured with an extension carrier may not be used tomonitor PDCCH configured for the extension carrier and with CRCscrambled by SPS C-RNTI in the WTRU-specific search space of theassociated carrier.

For an extension carrier, PDCCH with CRC scrambled by C-RNTI or SPSC-RNTI may be supported (e.g., only supported) in the WTRU-specificsearch space of the associated legacy carrier, even if the associatedcarrier is the primary carrier.

DCI formats specific to extension carriers may be described herein. TheDCI formats to decode in the WTRU specific search space may depend onthe transmission mode configured for the WTRU (e.g., in R-10).Transmission modes may correspond to different MIMO configurations.

In order to reduce the number of blind decoding attempts, a set (e.g.,limited set) of DCI formats may be supported for extension carriers.Extension carriers may be configured within a small system bandwidth.DCI formats having full flexibility in resource block (RB) assignmentmay not be used.

If CRS is not configured in an extension carrier, a WTRU configured withthe extension carrier may be expected to be configured in transmissionmode 9 using a certain set of DCI formats (e.g., DCI format 1A and 2C).

DCI format(s) and/or transmission mode(s) may be defined to supportextension carriers (e.g., in R-11) where such DCI format(s) and/ortransmission mode(s) may be used with/without CRS in a carrier.

PDSCH starting position in extension carrier may be described herein.The starting OFDM symbol for the PDSCH of a serving cell in the firstslot in a subframe may be dynamically varied on a per subframe basisindependently for each carrier, for example, depending on the number ofOFDM symbols occupied by the PDCCH region located to the first part ofeach subframe (e.g., in R-10). The start of the PDSCH region may besemi-statically configured when using cross-carrier scheduling.

PDCCH may not be configured in an extension carrier, so that the PDSCHof the extension carrier may be transmitted in the carrier from thefirst OFDM symbol in the first slot in a subframe (e.g., in R-11). ThePDSCH may be transmitted starting from the n-th OFDM symbol where N>1,for example, in order to reduce inter-cell interference to an adjacentcell where PDCCH is configured in the carrier.

The WTRU configured with an extension carrier may know that the startingposition for the data region on the extension carrier upon which theintended PDSCH is transmitted.

The starting OFDM symbol for PDSCH of an extension carrier may be thesame as that of the associated legacy carrier in which PDCCH of theextension carrier is transmitted (e.g., cross-carrier scheduled). TheWTRU may use the same PDSCH starting position for the legacy carrier forthe extension carrier.

The starting OFDM symbol for PDSCH of an extension carrier may besignaled in a (e.g., newly defined) PDSCH starting position field in thecorresponding PDCCH of the extension carrier where the PDCCH may betransmitted in an associated legacy WTRU. After decoding the PDCCH of anextension carrier, the WTRU may know the PDSCH starting position for theextension carrier. A PDSCH starting position field may be defined inPDCCH of an extension carrier. For example, the TPC bit field (e.g.,with 2 bits) in the R-10 PDCCH with DCI format 1/1A/2/2A/2B/2C may bereplaced by the PDSCH starting position field.

The WTRU may use the value indicated in the PCFICH on the serving cellcarrying the PDSCH.

A higher-layer configuration parameter may be provided (e.g., on asemi-static manner) for the WTRU for the serving cell upon which PDSCHis received. The higher layer configured parameter value may differ fromthe value signaled on the PCFICH on the cell carrying the PDSCHtransmission.

Any combination of the above procedures may be used for the WTRU to knowthe starting position for the PDSCH transmission on the extensioncarrier.

Carrier segments in MBSFN subframes may be described herein. A subset ofthe DL subframes in a radio frame (e.g., 10 msec) on a serving cell maybe configured as MBSFN subframes by higher layers (e.g., in R-10). EachMBSFN subframe may be divided into a non-MBSFN region and/or an MBSFNregion. In the MBSFN subframes configured for PMCH transmission, a WTRUmay not monitor a PDCCH of a serving cell (e.g., PCell or SCell) inorder to receive PDSCH intended for the WTRU. In a MBSFN subframe whichis configured for PMCH transmission, if a WTRU is configured to usecarrier segments for a serving cell (e.g., PCell and/or SCell), the WTRUmay transmit (or be configured to transmit) PDSCH in the carriersegments of the serving cell. For example, when PMCH is transmitted onthe PCell in a MBSFN subframe, the WTRU (e.g., configured to use carriersegments for the PCell) may receive PMCH on the PCell and/or PDSCH inthe carrier segments of the same PCell in the same MBSFN subframe. Forexample, as shown in FIG. 22 . The PDCCH, corresponding to the PDSCHtransmitted in the carrier segments, may be transmitted in the PDCCHregion (e.g., non-MBSFN region) of the PCell or be cross-carrierscheduled from another serving cell configured for the WTRU.

If a SCell configured for the WTRU has carrier segments for the WTRU,then the WTRU may be configured to receive PDSCH (e.g., intended for it)within the carrier segments of the SCell in a MBSFN subframe. In MBSFNsubframes, the CP length used in the non-MBSFN region (e.g., PDCCHregion) may be the same CP length as used for subframe 0. The CP lengthused for the non-MBSFN region of a MBSFN subframe may be different fromthat used for the MBSFN region of the same subframe. When carriersegments are configured for a serving cell, if the CP lengths for thenon-MBSFN region and MBSFN region, respectively, in a given MBSFNsubframe on the serving cell are different, then the first one or twoOFDM symbols (e.g., corresponding to the non-MBSFN region) in the MBSFNsubframe may not be used for PDSCH transmission in the carrier segments.The OFDM symbols (e.g., all OFDM symbols) (e.g., including the non-MBSFNregion and, for example, with a different CP length than the CP used inthe MBSFN region) of the carrier segments in the MBSFN subframe may beused for the PDSCH transmission for a WTRU configured with the carriersegments.

A WTRU configured with carrier segments of a serving cell may beconfigured to receive both PDSCH and PMCH (e.g., simultaneously) in agiven MBSFN subframe where PMCH is received on the serving cell (e.g.,PCell), while the PDSCH, intended for the WTRU, may be transmitted inthe carrier segments. The CP length used for the carrier segments mayfollow the CP length used for the linked main carrier OFDMsymbol-by-OFDM symbol.

As in the MBSFN region of the main carrier, the extended CP may be usedfor the MBSFN region of the carrier segments and transmission, if any,in the non-MBSFN region of the carrier segments may use the same CP asused for subframe 0. In MBSFN subframes, if PDSCH is transmitted incarrier segments, the starting OFDM symbol for the PDSCH of the carriersegments may be configured and/or signaled to WTRU(s) (e.g., via L2/3signaling).

In MBSFN subframes, the transmission mode (and/or antenna ports) usedfor carrier segments may be set for each WTRU configured for the carriersegments. TM 9 with extended CP may be used (e.g., always used) forPDSCH transmission in carrier segments.

In MBSFN subframes not used for PMCH transmission, when carrier segmentsare configured for a serving cell, the configuration of the carriersegments, such as frame structure, TM, antenna port configuration,and/or CP length, etc, may be identical to that of the linked servingcell. For example, PDSCH transmission in the non-MBSFN region of thecarrier segments may use TM 9. The PDSCH in the carrier segments may useextended CP.

FIG. 23 is a diagram illustrating an example of PDSCH transmission incarrier segments in the MBSFN subframes.

PDSCH transmission on extension carrier in MBSFN subframes may bedescribed herein. In the MBSFN subframes configured for PMCHtransmission, a WTRU may not monitor a PDCCH of a serving cell (e.g.,PCell or SCell) in order to receive PDSCH intended for the WTRU (e.g.,in R-10). The PDSCH may be transmitted on the extension carrier in aMBSFN subframe.

In MBSFN subframes (e.g., except the subframes indicated by higherlayers to decode PMCH), when a WTRU is configured with a given extensioncarrier, the WTRU may attempt to decode a PDCCH of the extension carrier(with CRC scrambled, for example, by the C-RNTI, the EC-RNTI, orequivalent RNTI, with a corresponding DCI format intended for the WTRU)where the PDCCH may be cross-carrier scheduled by a serving cell and/orbe transmitted on the extension carrier. The WTRU, upon detection of aPDCCH of the extension carrier, may decode the corresponding PDSCH onthe extension carrier in the same subframe.

The WTRU may be configured for transmission mode 9 (or a new R-11 TM)with a given extension carrier supporting TM 9 (or a new R-11 TM).

In MBSFN subframe including the subframes indicated by higher layers todecode PMCH, when a WTRU is configured with a given extension carrier,the WTRU may follow the same procedure a described above regarding TM 9.

In a MBSFN subframe, an extension carrier may support (e.g., onlysupport) TM 9 (or a new R-11 TM).

In MBSFN subframes, including the subframes indicated by higher layersto decode PMCH, when a WTRU is configured with a SCell, the WTRU mayattempt to decode a PDCCH of the SCell (with CRC scrambled, for example,by the C-RNTI or equivalent RNTI, with a corresponding DCI formatintended for the WTRU) where the PDCCH may be cross-carrier scheduled bya serving cell and/or be transmitted on the SCell. The WTRU, upondetection of a PDCCH of the SCell, may decode the corresponding PDSCH onthe SCell in the same subframe. The carrier segments may be configuredfor the concerned SCell.

Synchronization for extension carriers/carrier segments may be describedherein. If PSS/SSS is not transmitted on an extension carrier (or a newR11 carrier), a WTRU configured with the extension carrier (or new R11carrier) may be used to obtain/maintain time and/or frequencysynchronization for the extension carrier without PSS/SSS. The WTRU mayobtain other information (e.g., cell ID and CP length) for initialsynchronization. Several considerations for synchronization proceduresfor the extension carrier may be described herein.

Without the PSS/SSS in the extension carrier, the WTRU may receive somesynchronization information of the concerned extension carrier using,for example, dedicated configuration signaling (e.g., RRC signaling)from a legacy serving cell. The synchronization information may includethe carrier frequency, the system bandwidth, the cell ID (e.g.,parameter physCellId), the CP length of the extension carrier, and/orsome timing information (e.g., timing offset between multiple servingcell transmissions in the DL) among others, as part of the systeminformation element, system information block and/or configurationparameters. If the PBCH is transmitted on the extension carrier, some ofthe synchronization relevant information (e.g., such as the systembandwidth and/or some timing information, among others) may be carriedin the PBCH. The PBCH may include in a higher layer message (e.g. RRCmessage) an indication regarding which reference/associated serving cellthe WTRU may be based on to obtain/maintain the time and/or frequencysynchronization for the extension carrier. A list of physicalsignal(s)/channel(s) configured/carried in the concerned extensioncarrier (e.g., including the configuration parameters of the respectivephysical signal/channel, if any) may be provided for the WTRU, forexample, as part of the system information element, system informationblock, and/or RRC configuration parameters) for the extension carrier.Depending on which physical signal(s)/channel(s) relevant tosynchronization is not transmitted in the extension carrier, the WTRUmay determine how to acquire synchronization information (and/or todrive/maintain synchronization).

Regarding Cell ID detection, in the case of no PSS/SSS transmission onan extension carrier (or a new R11 carrier), the WTRU may be providedwith the cell ID of the extension carrier through RRC signaling from theassociated legacy serving cell.

Regarding CP length detection, the WTRU may be provided with the CPlength of the extension carrier through RRC signaling from theassociated legacy serving cell (e.g., similar to cell ID detection).

Regarding time synchronization (e.g., symbol and frame synchronization),when the WTRU is configured with an extension carrier and the associatedserving cell (e.g., the PCell), both of which may be transmitted fromthe same site and may be accurately synchronized in time, the WTRU mayuse the extension carrier time synchronization obtained through theassociated serving cell. For example, the WTRU may accomplish initialtime synchronization of the extension carrier based on the timesynchronization of the associated serving cell, which may be done basedon the PSS/SSS and CRS signals on the associated serving cell. Someinter-band aggregated carriers (e.g., those transmitted from the samesite) may apply the same principle. As a function of the propagationcharacteristics of the aggregation carriers, which may be dependent(e.g., mainly dependent) on the deployment layer/scenario, the resultingburden onto the WTRU receiver design to cope with Rx windowuncertainties may become cumbersome.

If the extension carrier and the associated serving cell are transmittedfrom different transmission points (e.g., RRH), different delaypropagation characteristics may result. The WTRU may not use theextension carrier timing synchronization obtained through the associatedserving cell. The WTRU may acquire the timing synchronization for theextension carrier using one or more of the followings.

If the CRS is transmitted on the extension carrier, the WTRU may use theCRS as a potential reference for time synchronization on the extensioncarrier. The CRS, which is configured/transmitted on the extensioncarrier, may be a configuration different than the R10 CRS. For example,the CRS may not be configured to be transmitted every subframe on theextension carrier. It may be configured to be transmitted every Nsubframe, where N>1.

If other RS (e.g., unprecoded DM-RS or CSI-RS) is configured/transmittedon the extension carrier, the WTRU may use the RS (e.g., combined withanother RS and/or physical channel/signal) as a potential reference fortime synchronization on the extension carrier.

The WTRU may be provided through higher layer signaling with anaggregated legacy carrier (e.g., the associated PCell or another servingcell/carrier) which the WTRU may reuse the time synchronization of thelegacy carrier for the extension carrier.

The eNB may transmit either the PSS or the SSS on the extension carrierso that the WTRU may use the PSS and/or SSS for timesynchronization/tracking (e.g., combined with other physicalchannel(s)/signal(s), for example, CRS, DM-RS and/or CSI-RS, ifconfigured on the extension carrier).

The WTRU may be provided through higher layer signaling or L1 signalingtiming information (e.g., such as a time difference between theextension carrier and the associated or reference carrier).

Higher layer signaling (e.g., that is broadcasted or that uses dedicatedconfiguration signaling from the network) may indicate to the WTRU aserving cell which may be used by the WTRU as a DL timing reference forthe extension carrier. The WTRU may align the timing (e.g., system framenumber and/or subframe starting time) of the extension carrier with thatof the indicated serving cell.

Via higher layer signaling (e.g., RRC signaling), a timing offsetparameter (e.g., in terms of a time unit, Ts) may be indicated to theWTRU with and/or a reference/associated serving cell (e.g., PCell orSCell) serving as a timing reference such that the WTRU may determinethe timing of the reference serving cell. The WTRU may derive the timingof the extension carrier based on the timing of the reference servingcell and/or the configured/signaled timing offset parameter.

A reference signal or signals (e.g., CRS, un-precoded DM-RS, and/orCSI-RS) transmitted on the extension carrier may be used by the WTRU fortracking (or assisting) timing synchronization (e.g., aligning thesubframe starting time) for the extension carrier. The CRS may beconfigured similarly to the legacy CSI-RS (e.g., in terms of subframeconfiguration and/or zero power bitmap). For the un-precoded DM-RS, theprecode may be obtained through signaling.

Any one or a combination of the above procedures for timesynchronization with the extension carrier may be implemented.

Regarding frequency synchronization, when the WTRU is configured with anextension carrier and the associated serving cell/carrier, both of whichmay be transmitted from the same site and accurately synchronized infrequency/time, the WTRU may use the extension carrier frequencysynchronization obtained through the associated serving cell. Forexample, the WTRU may accomplish frequency synchronization (e.g.,including initial frequency synchronization) of the extension carrierbased on the frequency synchronization of the associated serving cell(e.g., which may be done based on the PSS/SSS and CRS signals on theassociated serving cell). As the aggregated carriers may be co-located,the changes in frequency, for example, due to Doppler may be the same onboth the carriers. Depending on the RF Rx implementation in the WTRU,for example, the intra-band aggregation scenarios may qualify for thisoperating principle.

If the extension carrier and the associated serving cell/carrier aretransmitted from different transmission points (e.g., RRH), thendifferent delay Doppler profiles on the extension carrier and associatedserving cell/carrier may occur. The WTRU may not use the extensioncarrier frequency synchronization obtained through the associatedserving cell. The WTRU may acquire/maintain the frequencysynchronization for the extension carrier using one (or a combination)of the followings.

The WTRU may acquire the carrier/center frequency of the extensioncarrier from the associated (e.g., reference) serving cell (or anaggregated carrier) where the carrier frequency may be provided for theWTRU, for example, as part of the system information element, systeminformation block, and/or RRC configuration parameters for the extensioncarrier.

The WTRU may track/maintain frequency synchronization using a referencesignal (e.g., the WTRU-specific RS, the un-precoded DM-RS, CRS, and/orCSI-RS) configured/transmitted on the extension carrier. The CRS may beconfigured similarly to the legacy CSI-RS, e.g., in terms of subframeconfiguration and/or zero power bitmap.

If the CRS is configured/transmitted on the extension carrier, the WTRUmay use the CRS as a potential reference for frequency synchronizationon the extension carrier. In this case, the CRS, which may beconfigured/transmitted on the extension carrier, may be a configurationdifferent from the R10 CRS. For example, the CRS may not be transmittedevery subframe on the extension carrier. It may be configured fortransmission every N subframe, where N>1.

If other RS (e.g., unprecoded DM-RS or CSI-RS) is configured/transmittedon the extension carrier, the WTRU may use the RS (e.g., alone orcombined with another RS or physical channel/signal) as a reference forfrequency synchronization on the extension carrier. For the un-precodedDM-RS, the precode may be obtained through signaling. For example, ifthe CRS (or the CSI-RS) is transmitted on the extension carrier, thenthe WTRU may utilize the CRS (or the CSI-RS) to conduct (or assist)frequency synchronization for the extension carrier.

The WTRU may be provided (e.g., through higher layer signaling) with anaggregated legacy carrier (e.g., the associated PCell or another servingcell/carrier), which the WTRU may reuse, the frequency synchronizationof the legacy carrier for the extension carrier.

The eNB may transmit the PSS or the SSS on the extension carrier suchthat the WTRU may use it for frequency synchronization/tracking (e.g.,alone or combined with other physical channel(s)/signal(s) (e.g., CRS,DM-RS and/or CSI-RS, if configured on the extension carrier).

The WTRU may be provided through (e.g., higher layer signaling or L1signaling) with frequency information such as frequency differencebetween the extension carrier and the associated (or reference) carrier.

For example, to reduce or eliminate the effect of frequency errorsarising from a mismatch of the local oscillators between the Tx and theRx, as well as Doppler shifting caused by any WTRU motion, the WTRU mayadjust/refine frequency (and/or time) synchronization using one (or acombination) of the followings:

Frequency offsets may arise from factors such as, but not limited to,temperature drift, ageing, and imperfect calibration. An equation forDoppler shift may be as follows:fd=(fcv/c)where fc may be the carrier frequency, v may be the WTRU speed in metersper second, and c may be the speed of light (3×10⁸ m/s). If fc is 2 GHzand v is 500 km/h, then the Doppler shift fd may be 950 Hz.

The WTRU may track/maintain frequency synchronization, for example,based on the frequency synchronization correction result of theassociated (e.g., reference) serving cell and the carrier frequencydifference between the extension carrier and the associated servingcell. For example, the carrier frequency offset estimate of theextension carrier may be given by:fc _(,offset,extensionCarrier) =α*fc _(,offset,servingCell) +β*g(fc_(,extensionCarrier) −fc _(,servingCell))where fc_(,offset,extensionCarrier) may be the frequency offset estimateof the extension carrier, fc_(,offset,servingCell) may be the frequencyoffset estimate of the associated serving cell, fc_(,extensioncanier)may be the center frequency of the extension carrier, fc_(,servingCell)may be the center frequency of the associated serving cell, α and β mayrepresent weighting coefficients/factors, 0<=α, β<=1, and g(.) mayrepresents a function of the carrier frequency difference between theextension carrier and the associated serving cell.

PSS and/or SSS may be configured/transmitted on an extension carrier.For time and/or frequency synchronization on the extension carrier, theWTRU may use one or a combination of the implementations describedherein (e.g., described with regard to when PSS and SSS are notconfigured on the extension carrier).

The WTRU may use one or a combination of PSS and/or SSS and CRS (orCSI-RS) transmission on the extension carrier, which may be configuredwith less frequencies and/or configured differently (e.g., in terms oftime and frequency grid/domain).

When PSS and/or SSS is transmitted on an extension carrier (for example,for the case that the aggregated carriers are not co-located), the WTRUmay obtain initial time and frequency synchronization from the PSSand/or SSS transmitted on the extension carrier, whileupdates/maintenance of its time and frequency reference may be obtainedfrom the scheduled CRS, CSI-RS, and/or un-precoded DMRS. The scheduledCRS may be configured similarly to the legacy CSI-RS in terms ofsubframe configurations and/or the zero power bitmap. For theun-precoded DM-RS, the precode may be obtained through signaling. ThePSS and/or SSS signals may be configured with longer periods compared tothe legacy period of 5 ms to mitigate interference and save energy.

Within some RBs, resource elements (e.g., additional resource elements)may be used (or reserved) for the transmission of RS (or synchronizationsignals).

Regarding Radio Link Failure (RLF)/Radio Link Monitor (RLM) forextension carriers, the WTRU may monitor the radio link quality of theextension carrier, for example, using a reference signal or signals(e.g., CRS, DM-RS, and/or CSI-RS, if available). During a certain period(e.g., configured by the network), the WTRU may assess radio linkquality of the extension carrier (e.g., evaluated against one or morethresholds configured by higher layers). Higher layer signaling mayindicate to the WTRU a set of subframes. The WTRU may not include thesesubframes in the set of subframe monitored for radio link for theextension carrier.

A WTRU (e.g., legacy) may be prevented from acquiring a carrier of a NewCarrier Type (NCT). NCTs may be supported for CA where a carrier of theNCT may be linked (e.g., associated) with a legacy carrier (e.g., aPCell) (e.g., in R11). The carrier of the NCT may be non-backwardcompatible and may not be stand-alone. For example, the carrier may notbe configured as a PCell for a WTRU (e.g., any WTRU including R8 to R10UEs and, for example, even R11 UEs) and the carrier may be (e.g., mayalways be) configured/aggregated with the associated legacy carrier. Fora NCT and, for example, a non-synchronized new carrier, PSS/SSSsequences (e.g. R8) may be transmitted. A legacy WTRU (e.g., R8 WTRU)may detect the PSS/SSS of the NCT, which may be undesirable as a WTRU(e.g., R8 WTRU) may camp on the non-backward compatible carrier.

If a WTRU (e.g., R8 WTRU) acquires synchronization to a NCT (e.g., bydetecting the PSS/SS of the NCT), the WTRU (e.g., R8 WTRU) may attemptto decode the system information of the (non-backward compatible)carrier as part of the cell synchronization/access procedure. Thisbehavior (of cell synchronization to the NCT carrier) may be unnecessaryby the WTRU (e.g., R8 WTRU) and/or may cause the WTRU (e.g., R8 WTRU),for example, to increase its power consumption and/or delay the overallcell search process.

Implementations may prevent a WTRU (e.g., a R8 WTRU) from accessing acarrier of the NCT.

The existing PSS/SSS sequences may be kept unchanged and may modify atime-domain and/or a frequency-domain position of the PSS/SSS of a NCT(e.g., the new time/frequency domain configuration of PSS/SSS).

The time-domain position of PSS and/or SSS of a NCT may be modified. Forexample, the OFDM symbol locations of PSS/SSS may be swapped such thatin the case of FDD, the PSS may be transmitted in the 2^(nd) to lastOFDM symbol of the first slot of (for example, subframes 0 and 5) andthe SSS may be transmitted in the last OFDM symbol of the same slot(e.g., after the PSS (for example, just after the PSS)). In the case ofTDD, the PSS may be transmitted in the last OFDM symbol in, for example,slot 1 and 11 and the SSS may be transmitted in the 3^(rd) OFDM symbolin, for example, subframes 1 and 6.

The time location of either SSS or PSS may be modified (or configured),while keeping the time-domain position of the either PSS or the SSSunchanged. For example, the SSS may be transmitted in the N-th OFDMsymbol after (or prior to) the PSS transmission, while excluding thelegacy SSS position, e.g., the 2^(nd) to last OFDM symbol of the firstslot of subframes 0 and 5 for FDD. N may be fixed or configured via highlayer signaling of the linked/associated legacy carrier. If a legacyWTRU detects and/or identifies the PSS of a NCT (so that it maydetermine the cell ID within the cell ID group), the legacy WTRU may notdetermine the cell ID group itself (e.g., due to failure of the SSSdetection, as the SSS position relative to the PSS may be changed).

The frequency location of the PSS and/or the SSS of a NCT may bemodified.

R8 may allow a 100 kHz raster for placing the LTE channel within theoperator owned bandwidth. A WTRU may scan carrier frequencies with a 100KHz interval during an initial cell search. The minimum carrier spacingwith contiguously aggregated component carriers may use 300 KHz topreserve the orthogonality for the subcarrier spacing of 15 KHz in theDL transmission (e.g., the least common multiple of [15, 100] KHz)(e.g., for LTE carrier aggregation). The center frequency position ofthe PSS/SSS may be offset from the center frequency of a NCTtransmission bandwidth, for example, such thatf_(ss,NCT)=f_(c,NCT)+f_(offset) where f_(c,NCT) may be the centerfrequency of the NCT transmission bandwidth (e.g., f_(c,NCT)=f_(c)+k*300KHz where f_(c) may be the lowest frequency in the operator owned bandand k is an integer value) and/or the offset for the PSS/SSS may bef_(offset)=15 KHz*c<300 KHz where c is an integer value. For example,the offset value may be a multiple of subcarrier spacing of 15 KHz andless than 300 KHz, e.g., f_(offset)∈{15, 30, 45, 60, . . . , 285}. Thecenter frequency position of the PSS/SSS (=f_(ss,NCT)) may not be in themultiple integer raster (100 KHz) such that the legacy WTRU may not beable to detect the PSS/SSS for the NCT. The offset value may be fixedand/or configured via high layer signaling of the linked/associatedlegacy carrier.

The existing PSS/SSS mapping to time and/or frequency domain may be keptunchanged and/or may define a new PSS and/or SSS sequences for a newcarrier type. For example, a 1^(st) part and a 2^(nd) part of the PSSsequence may be swapped and/or reverse order of sequence n as set forthbelow:

Swap 1^(st) part and 2^(nd) part of the PSS, for example, as set forthin:

${d_{u}(n)} = \left\{ \begin{matrix}e^{{- j}\;\frac{\pi\;{{un}{({n + 1})}}}{63}} & {{n = 31},32,\ldots\mspace{11mu},61} \\e^{{- j}\;\frac{\pi\;{u{({n + 1})}}{({n + 2})}}{63}} & {{n = 0},1,\ldots\mspace{11mu},30}\end{matrix} \right.$

Reverse order of PSS sequence, for example, as set forth in:

${d_{u}\left( {61 - n} \right)} = \left\{ \begin{matrix}e^{{- j}\;\frac{\pi\;{{un}{({n + 1})}}}{63}} & {{n = 0},1,\ldots\mspace{11mu},30} \\e^{{- j}\;\frac{\pi\;{u{({n + 1})}}{({n + 2})}}{63}} & {{n = 31},32,\ldots\mspace{11mu},61}\end{matrix} \right.$

Swap 1^(st) part and 2^(nd) part of the PSS sequence and reverse orderof PSS sequence, for example, as set forth in:

${d_{u}\left( {61 - n} \right)} = \left\{ \begin{matrix}e^{{- j}\;\frac{\pi\;{{un}{({n + 1})}}}{63}} & {{n = 31},32,\ldots\mspace{11mu},61} \\e^{{- j}\;\frac{\pi\;{u{({n + 1})}}{({n + 2})}}{63}} & {{n = 0},1,\ldots\mspace{11mu},31}\end{matrix} \right.$

It may be determined or checked whether the above modification has thesame correlation property (and/or a similar correlation property (e.g.,above a threshold level), as the legacy PSS sequence].

ZC sequences may be used for the PSS that may be modified, for example,by using a different set of root index u for N_(ID) ⁽²⁾.

A different set of two length-31 binary maximal length sequences forSSS1 in subframe 0 and SSS2 in subframe 5 may be used. The design of twonew m-sequences for NCT SSS may provide the same or similar performanceto that of R8.

An overlay of code may be implemented on the PSS (e.g., applying ascrambling sequence on the PSS). For example, the PSS sequence may beoverlaid with an overlay code o(n)=[1, −1, 1, −1, . . . , 1, −1] forn=0, 1, 2, . . . , 61 such that a polarity of odd numbered PSS sequence(e.g., all odd numbered PSS sequence) is reversed. The cross-correlationproperty of the ZC sequence may be checked with the overlay code.

The overlay code with a low correlation value may be obtained (forexample, through computer search). The overlay code may be fixed orconfigured via high layer signaling of the linked/associated legacycarrier.

No change may be made in the existing PSS/SSS sequence and/or resourcemapping. A legacy WTRU may be made to fail to acquire the MIB and/or theSIB.

A CRS design may be implemented, which is different from the followingR8 design. In R8, the reference-signal sequence r_(l,n) _(s) (m) may bedefined by

${{r_{l,n_{s}}(m)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\;\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2\; m} + 1} \right)}}} \right)}}},$m=0, 1, . . . , 2N_(RB) ^(max, DL)−1where n_(s) may be the slot number within a radio frame and l may be theOFDM symbol number within the slot. The pseudo-random sequence generatormay be initialized with c_(init)=2¹⁰·(7·(n_(s)+1)+l+1)·(2·N_(ID)^(cell)−N_(CP) at the start of each OFDM symbol, where

$N_{CP} = \left\{ {\begin{matrix}1 & {{for}\mspace{14mu}{normal}\mspace{14mu}{CP}} \\0 & {{for}\mspace{14mu}{extended}\mspace{14mu}{CP}}\end{matrix}.} \right.$

For Example, a CRS design may be implemented for NCT that may modify theinitialization of the pseudo-random sequence generator such thatc_(init,NCT)=2¹⁰·(7·(n_(s)+1)+l+1)·(2·N_(ID) ^(cell)+1)+2·N_(ID)^(cell)+N_(CP)+N_(NCT) where

$N_{NCT} = \left\{ {\begin{matrix}1 & {{for}\mspace{14mu}{NCT}} \\0 & {{for}\mspace{14mu}{legacy}\mspace{14mu}{carrier}}\end{matrix}.} \right.$

The N_(NCT) may be configured, for example, via high layer signaling ofthe linked/associated legacy carrier.

The new CRS may be overlaid with a scrambling code, which may be uniquefor the NCT. The overlay code may be fixed or configured via high layersignaling of the linked/associated legacy carrier.

The PBCH may be removed (e.g., completely removed) and/or the MIB forNCT may be obtained (e.g., via high layer signaling of thelinked/associated legacy carrier). If there is no PBCH for NCT, thelegacy WTRU may not be able to detect the PBCH for NCT.

Different time/frequency location (e.g., duty cycles, location ofsubframes and/or OFDM symbols) of PBCH for the NCT may be configuredfrom corresponding ones for the legacy carrier. Since the PBCH locationfor NCT may be changed relative to PSS/SSS location, the legacy WTRU maynot be able to detect PBCH for the NCT.

A different SI-RNTI may be allocated for NCT accessible UEs from theSI-RNTI value 0xFFFF allocated for legacy UEs. The value may be takenfrom the RNTI values that are reserved (e.g., for future use). Thelegacy UEs may not be able to find the SIB1 and/or associated systeminformation for the NCT that may be mapped to PDCCH/PDSCH.

A legacy WTRU may be prevented from reading the SIB1 from the NCT cellthat may not have the PDCCH configured. The legacy WTRU may be unable todecode the PDCCH with the SI-RNTI and may be unable to retrieve theSIB1. R11+ UEs may be able to retrieve the SIB1 based on SI-RNTItransmitted via E-PDCCH and/or provided with SIB1 related informationvia dedicated signaling.

A legacy WTRU may be prevented from accessing the cell, for example, bycausing the legacy WTRU to fail to properly decode and read an IE (e.g.,a mandatory IE), and may discard the MIB. For example, the NCT cell mayor may not broadcast its MIB with an invalid value for systemFrameNumberIE and may or may not include the proper SFN in the spare IE of the MIB.A R11+ WTRU may be configured to read and decode (e.g., properly readand decode) the SFN of the MIB from the NCT cell whereas a legacy WTRUmay not be able to properly decode the SFN and may discard the MIB.

The MIB and/or SIB1 information may be used to prevent the legacy WTRUfrom camping on the NCT cell, as a suitable cell for normal operation(e.g., which may be an alternative to causing a failure to the MIB/SIB1read procedure). For example, the legacy WTRU may continue its searchfor a suitable cell by having the NCT cell fail to meet the criteria ofa suitable cell.

The network may allocate a special CSG ID (e.g., exclusively for R12UEs) which may operate normally on the NCT. In SIB1 of NCT, the CSGindication may be set to TRUE and the CSG ID may be set, as the R12specifically allocated CSG ID. Upon reading the SIB1 with the CSGinformation, a legacy WTRU, not having the CSG ID on its CSG whitelist,may not select this NCT as a suitable cell.

The network/operator of the NCT may allocate (e.g., possibly allocate) aseparate PLMN ID for the network of the NCT cells. As part of deploymentof the NCT cells, the operator may choose to allocate a different PLMNID than the PLMN ID allocated to the legacy network. This NCT networkPLMN ID may be allocated as an equivalent PLMN to the NCT supporting theUEs and not to the legacy UEs. The legacy WTRU, upon PLMN and cellselection, may remove NCT cells as a candidate for a suitable cell tocamp on.

TAI and/or use of “forbidden tracking area for roaming” may beimplemented. For example, the NCT may be allocated with and broadcastits Tracking Area Code (TAC) in the SIB1 that may be different and/orseparate from backward compatible cells to which legacy UEs are allowedto attach. The legacy UEs may be provided, for example, as part of itssubscription data, a list of tracking areas that may restrict access tothe tracking area which includes the NCT cells. A group of NCTs in aPLMN (e.g., a particular PLMN) may belong to one or more of these R11+specific tracking areas.

A legacy WTRU may be prevented to access a NCT cell by settingcellBarred IE in the SIB1 as “barred”, which may make the cellunsuitable for normal service for the legacy WTRU. For R11+ UEs,separate information may indicate whether a cell is barred or not to R12may be included in the NCT cell system information. This information maybe an option, and in certain instances the information may not bepresent. A R11+ WTRU may use the legacy cellBarred information in theSIB1.

A legacy WTRU may be prevented from re-selecting to a NCT cell based,for example, on IDLE mode measurement “blacklist”. The WTRU may beprovided with a blacklist of intra-frequency and inter-frequency cellsby a serving cell via the SIB 4 and the SIB 5, respectively. For alegacy WTRU, the blacklist may be a list of PCIs of the NCT cells, whichmay be excluded by the legacy WTRU, as candidate cells for measurementand for cell reselection. The legacy may be able to detect the NCT celland may determine its PCI before applying it to the blacklist. NCT cellsmay not be included in the neighbor cell list as broadcasted in theSIB4/5 and read by the legacy WTRU in a serving cell. For NCT supportingWTRU (R11+ WTRU), the blacklist and IDLE mode measurement configurationmay be sent separately (e.g., in separate system information or set ofsuch information) broadcasted by the serving cell that may be readableby (e.g., only readable by) the NCT supporting UEs. The R11+ blacklistmay not comprise NCT cell PCIs. In case the R11+ WTRU does not detectthe new SIB information, the information in the legacy systeminformation for IDLE mode measurements may be applied. For example, theblacklist for R11+ UEs may be updated along with dedicated re-selectionpriority information (e.g., via a RRC Connection Release message whichmay be received when the WTRU moves to IDLE mode.

DL power allocation for extension carriers may be described herein. Forexample, if CRS is not transmitted on an extension carrier, the ratio ofPDSCH EPRE (effective power per RE) to CRS EPRE among PDSCH REs may notbe defined for the extension carrier. It may adversely affect the PDSCHdecoding operation by a WTRU on the extension carrier. There may be asignaling mechanism to indicate a DL power allocation on extensioncarriers.

Certain ratios (e.g., of PDSCH EPRE to CSI-RS EPRE and/or PDSCH EPRE toDM-RS) (WTRU-specific RS) EPRE may be signaled.

The eNB may set the power of extension carriers relative to the transmitpower of CRS corresponding to an associated BC CC where the relativepower (e.g., ratio) may be WTRU specific and/or signaled from the eNB.

PUSCH transmission in carrier segments may be described herein. Toimprove spectral efficiency in UL (e.g., in scenarios involving BWextension by narrow BWs), for example, carrier segments for UL may beapplied where one or more of the following characteristics may beimplemented.

For SRS transmissions, the WTRU may not transmit periodic SRS in carriersegments, but may be allowing aperiodic SRS transmissions. The soundingprocedure for carrier segments may follow the same procedure as that ofR-10 sounding procedure for the associated BC CC with the extended BW ofcarrier segments.

For guardband transmission, if the carrier segments are added into PCellwhere PUCCH is transmitted, one or more guard band(s) may be insertedbetween the carrier segment(s) and the PCell. The guard band(s) may be amultiple of 300 KHz.

For the maximum number of clusters for PUSCH, the maximum number ofclusters for PUSCH may be 2 (e.g., in R-10). If carrier segments areused in the UL for PUSCH (e.g., using non-contiguous resourceallocation), the maximum number of clusters for the PUSCH may beincreased (e.g., in R-11 and beyond).

For PUCCH transmission, carrier segments may be used for a PUCCHresource region. The PUCCH may not be transmitted in the carriersegments.

For UCI multiplexing in carrier segments, when UCI is multiplexing onPUSCH, UCI may be transmitted (e.g., only transmitted) in the BC CC andnot in any carrier segment (for example, when there is no CRStransmission in carrier segments).

For Power control for carrier segments, the same power may beestablished for the carrier segments and the linked BC CC, and

Carrier segments in the UL may use L1 signaling and/or L2/3 signaling.

LTE systems support scalable transmission bandwidths, one of 1.4, 2.5,5, 10, 15 or 20 MHz with 6, 15, 25, 50, 75, 100 resource blocksrespectively. Network operators may have access to spectrum allocationsthat do not exactly match one of the set of bandwidth sizes supported,for example when re-farming spectrum previously allocated to a differentwireless technology. It is contemplated that within the specifications,addition bandwidth sizes may be supported. Another possibility may be tospecify means for a WTRU to use extensions, such as carrier segments,allowing transmissions in an extended range of the PRBs. Extensioncarriers may additionally be used to increase spectral efficiency ofaggregated resources.

The methods described herein may be useful in enabling a WTRU to usecarrier segments and/or extension carriers, for example in deploymentscenarios such as that explained above.

The processes described above may be implemented in a computer program,software, and/or firmware incorporated in a computer-readable medium forexecution by a computer and/or processor. Examples of computer-readablemedia include, but are not limited to, electronic signals (transmittedover wired and/or wireless connections) and/or computer-readable storagemedia. Examples of computer-readable storage media include, but are notlimited to, a read only memory (ROM), a random access memory (RAM), aregister, cache memory, semiconductor memory devices, magnetic mediasuch as, but not limited to, internal hard disks and removable disks,magneto-optical media, and/or optical media such as CD-ROM disks, and/ordigital versatile disks (DVDs). A processor in association with softwaremay be used to implement a radio frequency transceiver for use in aWTRU, WTRU, terminal, base station, RNC, and/or any host computer.

What is claimed is:
 1. A method implemented in a wireless transmitreceive unit (WTRU), the method comprising: receiving configurationinformation associated with a serving cell, wherein the configurationinformation indicates at least a first subset of contiguously indexedresource blocks (RBs) of a carrier and a second subset of contiguouslyindexed RBs of the carrier; transmitting or receiving information in theserving cell using the first subset of contiguously indexed RBs of thecarrier; receiving a physical downlink control channel (PDCCH)transmission comprising downlink control information (DCI) associatedwith a radio network temporary identifier (RNTI), wherein the DCIindicates that the WTRU is to activate the second subset of contiguouslyindexed RBs of the carrier for communicating information in the servingcell; activating the second subset of contiguously indexed RBs of thecarrier for communicating information in the serving cell based onreceiving the PDCCH transmission; and deactivating the first subset ofcontiguously indexed RBs of the carrier for communicating information inthe serving cell based on receiving the PDCCH transmission.
 2. Themethod of claim 1, wherein the configuration information furtherindicates respective numbers of RBs comprised in the first subset ofcontiguously indexed RBs and the second subset of contiguously indexedRBs.
 3. The method of claim 2, wherein the configuration informationfurther indicates a first starting RB index of the first subset ofcontiguously indexed RBs and a second starting RB index of the secondsubset of contiguously indexed RBs.
 4. The method of claim 3, whereinthe second starting RB index is greater than the first starting RB indexplus the number of RBs comprised in the first subset of contiguouslyindexed RBs.
 5. The method of claim 1, wherein the first subset ofcontiguously indexed RBs or the second subset of contiguously indexedRBs is used to transmit information in an uplink of the serving cell. 6.The method of claim 1, wherein the first subset of contiguously indexedRBs or the second subset of contiguously indexed RBs is used to receiveinformation via a downlink of the serving cell.
 7. The method of claim1, wherein the DCI comprised in the PDCCH transmission includes a fieldor a flag indicating that the WTRU is to activate the second subset ofcontiguously indexed RBs of the carrier for communicating information inthe serving cell.
 8. The method of claim 1, wherein the configurationinformation comprises demodulation reference signal (DM-RS)configuration information specific to the first subset of contiguouslyindexed RBs of the carrier, the configuration information furthercomprising DM-RS configuration information specific to the second subsetof contiguously indexed RBs of the carrier.
 9. The method of claim 1,further comprising: deactivating the second subset of contiguouslyindexed RBs of the carrier for communicating information in the servingcell based on expiration of a time period at the WTRU; and re-activatingthe first subset of contiguously indexed RBs of the carrier forcommunicating information in the serving cell based on the expiration ofthe time period at the WTRU.
 10. The method of claim 9, wherein the timeperiod is started based on the WTRU being scheduled on the second subsetof contiguously indexed RBs of the carrier.
 11. A wireless transmitreceive unit (WTRU), comprising: a processor configured to: receiveconfiguration information associated with a serving cell, wherein theconfiguration information indicates at least a first subset ofcontiguously indexed resource blocks (RBs) of a carrier and a secondsubset of contiguously indexed RBs of the carrier; transmit or receiveinformation in the serving cell using the first subset of contiguouslyindexed RBs of the carrier; receive a physical downlink control channel(PDCCH) transmission comprising downlink control information (DCI)associated with a radio network temporary identifier (RNTI), wherein theDCI indicates that the WTRU is to activate the second subset ofcontiguously indexed RBs of the carrier to communicate information inthe serving cell; activate the second subset of contiguously indexed RBsof the carrier to communicate information in the serving cell based onreception of the PDCCH transmission; and deactivate the first subset ofcontiguously indexed RBs of the carrier for communicating information inthe serving cell based on reception of the PDCCH transmission.
 12. TheWTRU of claim 11, wherein the configuration information furtherindicates respective numbers of RBs comprised in the first subset ofcontiguously indexed RBs and the second subset of contiguously indexedRBs.
 13. The WTRU of claim 12, wherein the configuration informationfurther indicates a first starting RB index of the first subset ofcontiguously indexed RBs and a second starting RB index of the secondsubset of contiguously indexed RBs.
 14. The WTRU of claim 13, whereinthe second starting RB index is greater than the first starting RB indexplus the number of RBs comprised in the first subset of contiguouslyindexed RBs.
 15. The WTRU of claim 11, wherein the first subset ofcontiguously indexed RBs or the second subset of contiguously indexedRBs is used to transmit information in an uplink of the serving cell.16. The WTRU of claim 11, wherein the first subset of contiguouslyindexed RBs or the second subset of contiguously indexed RBs is used toreceive information via a downlink of the serving cell.
 17. The WTRU ofclaim 11, wherein the DCI comprised in the PDCCH transmission includes afield or a flag indicating that the WTRU is to activate the secondsubset of contiguously indexed RBs of the carrier to communicateinformation in the serving cell.
 18. The WTRU of claim 11, wherein theconfiguration information comprises demodulation reference signal(DM-RS) configuration information specific to the first subset ofcontiguously indexed RBs of the carrier, the configuration informationfurther comprising DM-RS configuration information specific to thesecond subset of contiguously indexed RBs of the carrier.
 19. The WTRUof claim 11, wherein the processor is further configured to: deactivatethe second subset of contiguously indexed RBs of the carrier forcommunicating information in the serving cell based on expiration of atime period at the WTRU; and re-activate the first subset ofcontiguously indexed RBs of the carrier to communicate information inthe serving cell based on the expiration of the time period at the WTRU.20. The WTRU of claim 19, wherein the processor is configured to startthe time period based on the WTRU being scheduled on the second subsetof contiguously indexed RBs of the carrier.